SSEWAJJE

CBC EDITION S.1-

S.4

CONCISE APPROACH TO NEW CURRICULUM QUESTIONS

 STRUCTURE OF THE UCE PHYSICS PAPER P53

Item Element of construct Topics covered

SECTION A: Compulsory

Item one Understands how waves are Nature of light; reflection of light at plane
generated, propagated and their surfaces
application in everyday life
Reflection of light at curved surfaces

Refraction, dispersion, and colour

Lenses and optical instruments

General wave properties

Sound waves

Item Understands the structure of Atomic models

atoms, nuclear processes and
Two Nuclear processes
their application in everyday life.

Item Understands solar system, The solar system

galaxies, stars, satellites & digital
Three Stars and galaxies
communication in everyday life
Satellites and communication

Digital electronics

SECTION B

PART I

Item four Understands effect of force and Measurements in Physics

and five heat on properties of matter
States of matter

Effects of forces
 Work, energy, and power

Turning effect of forces, centre of

gravity, and stability

Pressure in solids and fluids

Mechanical properties of Materials and

Hooke’s law

Linear and non-linear motion

Temperature measurements

Heat transfer

Expansion of solids, liquids, and gases

Heat quantities and vapours

PART II

Magnets and magnetic fields

Appreciates electricity and Electromagnetic effects

Item Six magnetism in everyday life Electrostatics

and
Introduction to current electricity
Seven
Voltage, resistance and Ohm’s law

Electric energy distribution and

consumption

NOTE:

 Section A will comprise of three compulsory items

 Section B comprises of Part I and Part II each having two questions and a learner
answers one question from each part.
In total five questions must be attempted by the learner.
 A concise approach to new curriculum physics questions by Buyinza David

WAVES AND LIGHT

Item 1

The manager of a certain shop is faced with several challenges as highlighted below

 Drinks from the fridge keep getting stolen, initially he could see the fridge directly but it’s now
covered by a shelf. The manager could not afford to install a camera because of their price.

 The manager could see near objects clearly but whenever he could look at a distant object it was
unclear.

 Music played from a nearby bar was so loud. The sound was more disturbing at night than during
the day.

The owners of the bar claimed that their speakers produced sound of wavelength 1cm which they
thought was not harmful to anyone’s ear

Hint

Speed of sound in air =330ms-1

Task

a) Using your knowledge of physics

b) Identify which measures the manager of the store could take to be able to view the fridge
c) Explain why the manager of the store could not see far objects clearly and what he
could do to improve his vision
d) Determine if the sound from the bar was harmful or not and explain why the sound was
clear during night than during the day.

ITEM 2

On a sunny day, peter from his garden carrying some maize and moving towards a tall wide tree to take a
shelter hears an explosion of seed near him and after a short time he hears a successive similar explosion
that appears to be coming from the tree. On his way, very thirsty, he notices a pool of water in front which
appears to move away as he approaches it. When he reaches the tree, he realizes that the tree does not
contain explosive seeds. Peter sees a circular glass in the tree and he recalls that he can use it to start fire
which he could use to roast his maize and eat, after which he could sleep off till night. The fire was lit
successfully when the glass was placed at a distance of 20cm from the dry grass. Looking for Peter, is a
 A concise approach to new curriculum physics questions by Buyinza David

friend with a torch who finds him in a black shirt with yellow spots at night. The colour of the shirt leaves
Peter and his friend confused.

Hint

The glass is curved outwards on both surfaces

Peter’s cloth was blue with red spots during the day.

Second sound was heard after 1.8s

Speed of sound in air is 330ms-1

Task

a) Help Peter to find out why he heard two similar successive sounds
b) Write down the two natural phenomena that resulted into the pool of water that Peter saw
c) Describe how the pool of water appeared in front of him
d) Describe how the glass was able to burn the glass
e) Using calculations what is the power of the glass

f) Distance from the tree to where Peter heard the explosion of the seed

Item 3

In certain music concert that took place at night, a man played a guitar on a floating stage surrounded by
disco lights flashing red, blue and green in the middle of the lake. The audience on the boats and shores
were wearing white clothes with yellow spots on them. The audience was surprised about the new
appearance of the colour of their clothes. The sound waves from the guitar travel through the air with a
frequency of 𝟒𝟒𝟎𝑯𝒛. The organizers also projected laser light, that travels through air with a frequency
of 𝟒.𝟕×𝟏𝟎𝟖𝑯𝒛 illuminating waves on the lake surface to aid visibility. On the shores of a lake was a tall
storied building a distance of 𝒙𝒎𝒆𝒕𝒓𝒆𝒔 away from the floating cruise. A lady on the floating boat cruise
bearing the floating stage noticed that the guitar sound was heard twice every time the guitar was played.
Using a stop watch, she got the time interval between the first and second sound heard to be 2s.

Hint: 𝑆𝑝𝑒𝑒𝑑 𝑜𝑓𝑠𝑜𝑢𝑛𝑑𝑖𝑛𝑎𝑖𝑟=𝟑𝟑𝟎𝒎𝒔-1 𝑆𝑝𝑒𝑒𝑑𝑜𝑓𝑙𝑖𝑔ℎ𝑡𝑖𝑛𝑎𝑖𝑟=𝟑.𝟎×𝟏𝟎𝟖𝒎𝒔-1

Task:

As a physics student;

a) Help the lady understand why she heard the sound of the guitar twice.
 A concise approach to new curriculum physics questions by Buyinza David

b) And help her know the distance between the lake shore and the boast
c) cruise.
d) Clearly explain why the colour of the clothes of the audience kept on changing
when coloured lights flashed on them.
e) Why was laser source of light preferred to provide laser light that enhanced visibility in
the late hours of the night.

Item 4

A new company has just been built next to your home, and while they have hired security guards, the
security cameras they intended to purchase are currently out of stock. At the moment, they are looking
for a basic tool that would enable them to view over the wall and what is outside when they are inside
the perimeter fence. In addition, the company has been advised to install a laser rather than a regular
lightbulb for night time security.

Hint

Available is a mirror and glass prism

The laser chosen for the security system has a wavelength of 532x10-9m

Speed of light in a vacuum is 3x108ms-1

Frequency of laser suitable for security system should be less than 6x1014Hz

Task

As a physics student

a) Choose between a mirror and a glass prism for the design of the simple instrument. Explain your
choice with reasons and use a diagram to illustrate the design and operation of the simple
instrument
b) Explain to the company how light from the regular lightbulb is different from a laser and advise
on whether the laser they purchased is suitable for their needs
 A concise approach to new curriculum physics questions by Buyinza David

Item 5

In a classroom activity, senior three students of your school are presented with the learning aids shown
in figure 1(a), 1(b) and 1(c)
 A concise approach to new curriculum physics questions by Buyinza David

The students are required to:

a) Describe the formation of the phenomenon shown in figure 1(a) in a class room setting
b) Explain why a physical rain bow appears curved and why its position is
opposite to that where the sun is
c) State the general name of the waves shown in figure 1(b)
d) Explain the effect of the two radiations at the extreme ends of figure 1(b) on
photographic plates
e) Explain the usefulness of visible radiations
f) Explain the patterns of the radiations shown in figure 1(b)
g) Use figure 1(c) to determine the amplitude and frequency of the sound waves

The senior three students have failed to do the assignment due to lack of knowledge and they
have approached you to help them.

Task

Assist the senior three students to do their class room activity. Hint Velocity of sound in air is
330ms-1

Item 6

Two people stood in the middle of two cliffs at an unknown distance between them. The woman
calls the boy and she hear herself 5 seconds later and the boy hear the second sound after 4
seconds. The two discovered that their sound was clearer at night than during the day. The
scenarios left them confused without understanding the magic in the hall.

TASK:

As a physics student;

a) What is the scientific name is given to this second sound?

b) Help the two people understand why the sound was clearer at night than that
during the day.

Light from air is made to strike the surface of alcohol of refractive index of 1.36 such that the
incident

light makes an angle of 200 with the normal at the point of incidence.

1
 A concise approach to new curriculum physics questions by Buyinza David
TASK:

a) What physics term is given to these phenomena and state the laws that govern them.

b) What is the angle of refraction as light passes the air-alcohol interface? (3 scores)

Item 7

In a certain company, the workers organized an end of year party in the company’s hall. The hall
was decorated and coloured bulbs flashing blue, yellow and green were connected all around at
the entry and inside. Music was played and some special communications from top bosses.
Workers were dressed in clothes of different colours. The workers observed the sound from the
musical

instruments were prolonged, noisy and unclear and still they were confused why their clothes
changed colour from their original colours.

Task

As a physics student help the workers understand why

a) The sound was pronged, unclear, and noisy

b) Why the colour of their clothes kept on changing under different lights
c) The colour of blue dress with red strips under green light

Item 8

A student putting on a blue shirt and a yellow trouser stand between two vertical walls. He
makes a loud sound while seeking for help. He hears the first echo after 2 seconds and the
second echo after 3 seconds. Three members of the rescue team arrived each had a torch
producing green, red and white light. The colour of the clothes the student was putting changed
whenever each torch was lit. This brought confusion among the members of the rescue team

Hint

speed of sound in air is 330ms-1

Task

a) As a physics student help the rescue team understand

b) The origin of the two echoes
c) The distance between the walls
 A concise approach to new curriculum physics questions by Buyinza David
d) Why the colours of the clothes kept on changing when different lights were lit

Item 9

The attendant of a swimming pool that is located at Kawempe screamed loudly when the phone
he was holding accidentally fell in the swimming pool. The attendant was confused that on
looking down into the water, he noticed his appearance and the phone appeared nearer to the
water surface. When he tried to pick it with his hand, he could not reach it and his appearance
was disappearing the moment his hand was in the water. While returning home later, he noticed
that a pool of water appeared in the middle of the tarmac but disappeared whenever he
approached it.

Along the way, he boarded a taxi and he sat next to driver but along the way he wondered how
the driver was able to see approaching vehicles to his car.

Task:

As a student of physics, help the attendant to know why:

(a) He noticed his appearance disappearing when he put his hand in water
(b) He was unable to reach his phone with his hand yet the phone seemed to
be nearer to the surface of the water in the pool.
(c) He noticed a pool of water on the road that disappeared whenever he approached it.
(d) The driver was able to see the approaching vehicles to his taxi (give the image formation)

Item 10

A brass band was invited to play during a celebration near a tall building, a distance slightly more
than 17 m away. Two friends standing in the same direction and in line with the playing band,
heard the sound from the band at different intervals of time which attracted them to go and attend
the celebration. On arrival, the sound they heard was unclear, confused and indistinct. Later in
the night during the cerebration, coloured lights flashing red, blue and green made the colours of
their clothes look different from the original colours which puzzled them.

Hint: Speed of sound in air = 330 ms-1

The two friends heard sound after 4s and 5s, respectively.

The friends were originally wearing yellow clothes.

3
 A concise approach to new curriculum physics questions by Buyinza David
Task:

As a physics student, help the two friends to understand why;

(a) they heard the sound at different intervals.

(b) the sound they heard was unclear, confused and indistinct.
(c) the colour of their clothes kept changing when coloured
lights flashed on them.

Item 11

The students in a particular class visited a laboratory with a white bulb and a red one, to observe
a glass

Tank filled with water with a white base at the bottom. Modifications were made to create a
shallow end on one side of the tank using glass material. To their surprise, when they struck the
water's surface at the shallow end with a long rectangular rod at a frequency of 80 Hz, they
noticed that the spacing between successive crests changed from 2.5cm to 5cm. Additionally,
they were disturbed by the distortion of ripples as they struck the tank walls. They were also
surprised to see the base turning black when it was replaced with a yellow sheet and the red lights
switched on.

Hint; the glass tank would break if the velocity of the waves that hit it is greater than 20ms-1

Use your knowledge of physics to:

a) Determine if the ripple tank will break.

b) explain the reason for the change in the distance between the ripples and its
impact on the velocity of the ripples.
c) explain what distorted the waves and how it could have been reduced.
d) explain why the yellow sheet changed colour when the red lights were switched

Item 12

A certain man went for tooth extraction in a clinic with his 8-year-old son. The dentist was so
busy and so asked his nurse to look for an optical instrument of radius of curvature 20cm, that
this would give him the best magnification. The average length of a mature human tooth is 3cm.
To achieve the best results, the nurse was advised to have a tooth 15cm from the instrument. As
soon as they arrived home late in the evening, the 8yearold son started narrating to his siblings
 A concise approach to new curriculum physics questions by Buyinza David
and their mother and the neighbours in the next room who had closed their room to sleep heard
the conversation. The neighbour felt sorry to the man.

HINT

Available optical instruments were concave mirror and convex lens of the same focal length.

Task.

As a learner of physics,

a) Advise the nurse on the optical instrument that would best extract the tooth.

b) Help to explain why the neighbour was able to hear the conversation from the 8-
year-old boy in the other room.

Item 13

A trainee learning to drive a car caused an accident because he saw something like a pool of
water on the tarmac highway which made him afraid of falling into it. Fortunately, He did not get
serious injuries and was rushed to the nearby hospital He was diagnosed with radiation of
wavelength 1×10-10 cm to check if none of his bones had got a fracture. He got surprised to see
the structure of the bones of his leg on an x-ray screen yet they had not cut his leg.

Hint:

The radiation is electromagnetic in

nature.

The speed of light=3.0×10^8 ms -1

Task:

Using the knowledge of physics:

(a) Explain to the trainee the incident which caused the accident. (05scores)
(b) Determine the frequency of the radiation that was used, and what would be the
wavelength if the frequency of the radiation was 85Hz? (07scores)
(c) What are the dangers of the radiation used in diagnosing the patient. State any
Precautions which should be taken to reduce on the dangers you have mentioned.
(04scores)
5
 A concise approach to new curriculum physics questions by Buyinza David
Item 14

During an attack of rebels in a certain district, two students hid themselves at the roof top of one
of the buildings, it was risky for them to observe the soldiers around the corners and gather

information to make informed decisions while minimizing exposure to danger. They noticed a
muzzle flash light followed by louds sounds of gun shots which was directly over a village. Some

distance behind the village is a mountain. They listened carefully and realized that, for each
muzzle flash, they can hear a loud sound of gunshot followed by a quieter one. The time between
seeing a flash over the village and hearing the first sound of a gun is 4 seconds.

Hint: Two plane mirrors, plastic tube, glue, craft knife and marker were available for the
students at the rooftop.

Speed of sound in air = 330 ms-1

Task

As a physics student, advise the two students on how to;

a) To check for soldiers around corners and in blind spots

b) Know why they heard two sounds for each muzzle flash

c) Identify how far away is the village from the students

Item 15

In a certain music concert that took place at night, a man played a guitar on a floating stage
surrounded by disco lights flashing red, blue and green in the middle of the lake. The audience on
the boats and shores were wearing yellow clothes with black spots on them. The audience was
surprised about the new appearance of the colours of their clothes. The sound waves from the
guitar travel through the air with a frequency of 𝟒𝟒𝟎𝑯𝒛. The organizers also projected laser
light, that travels through air with a frequency of 4.7×𝟏𝟎^𝟖𝑯𝒛 illuminating waves on the lake
surface to aid visibility. The shores of the lake were 𝟏𝟓𝒎 away from a tall storage building.
Boys A and B standing in the same direction and in line with the playing music from the lake
heard the sound at different intervals of time which attracted them to go and observe what was
taking place at the lake. Boy A heard the sound after 3s and boy B heard the sound after 4s.
 A concise approach to new curriculum physics questions by Buyinza David
Hint:

(𝑆𝑝𝑒𝑒𝑑 𝑜𝑓 𝑠𝑜𝑢𝑛𝑑 𝑖𝑛 𝑎𝑖𝑟=𝟑𝟑𝟎𝒎𝒔-1, speed 𝑜𝑓 𝑙𝑖𝑔ℎ𝑡 𝑖𝑛 𝑎𝑖𝑟=𝟑.𝟎×𝟏𝟎𝟖𝒎𝒔−𝟏)

Task:

As a physics student;

a) Help the two boys to understand why they heard the sound at different intervals.
b) Clearly explain why the colour of the clothes of the audience kept on
changing when coloured lights flashed on them.
c) Why was laser source of light preferred to provide laser light that enhanced
visibility late in the late hours of the night.

Compare the wave length of the sound waves and laser light waves in air medium.

Item 16

A war erupted in a certain mountainous areas surrounded by small water bodies where soldiers
only communicated by throwing a stone in water to alert their colleagues of danger ahead.
Instead, this alerted their enemies. One of the soldiers had small sizable plane mirrors and torn
paper box in his bag. Their leader sent spies to peep behind hills to see if the enemies were hiding
there but many were captured and killed. They totally lacked knowledge on how to solve this
problem. The enemy troops had a radio call that was used for communication and wave forms of
wave length were produced on the receiver’s computer clearly indicating the amplitude, period
and time taken for the wave to reach the receiver at the headquarter. One afternoon, it threatened
to rain and bright colours of different kind spread in the skies. This scared the soldiers even more.

Hint;

A graph obtained from the receiver’s computer

7
 A concise approach to new curriculum physics questions by Buyinza David
Task:

As a physics student, help the soldiers to;

a) Understand why the throwing of the stone in water always alerted their enemies

b) Know the best way they could reduce the rate at which their spies were being
killed and captured.
c) Understand the strange appearance of the skies that sent them to hide outs.
d) Determine frequency at which the waves reached the receiver at the home
base of the army.

Item 17

During a science project, learners are given two mirrors; a concave mirror of focal length 20cm
and a convex mirror of focal length 20cm.

Task:

As a learner of physics;

a) help the students to determine which mirror forms a bigger image of a man of
height 4cm standing 25 cm a way from each of the mirror.
b) write a brief report about the nature of image formed by each mirror advise
which mirror is suitable for use as driving mirror

Item 18
A brass band was invited to play during a celebration near a tall building, a distance slightly more
than 17 m away. Two friends standing in the same direction and in line with the playing band,
heard the sound from the band at different intervals of time which attracted them to go and attend
the celebration.

On arrival, the sound they heard was unclear, confused and indistinct. Later in the night during
the cerebration, coloured lights flashing red, blue and green made the colours of their clothes
look different from the original colours which puzzled them.

The two friends heard sound after 4 s and 5 s, respectively and were originally wearing
yellow clothes. Hint (Speed of sound in air = 330 m𝒔−𝟏)

Task:

As a physics student, help the two friends to understand why;

 A concise approach to new curriculum physics questions by Buyinza David
a) they heard the sound at different intervals.
b) the sound they heard was unclear, confused and indistinct.
c) the colour of their clothes kept changing when coloured lights flashed on them.

Item 19

Long time ago eclipses were considered as a message from the gods sine the people in that age
dwelt so much in the spiritual realm than the scientific word. But with the development of
science and technology, eclipses can now easily be explained scientifically instead of spiritually.

Whenever eclipses occur many people gather out in open places to watch the beautiful view of
the heavenly bodies as they align themselves in a beautiful display.

However, in most remote areas of Uganda some people still observe the eclipse directly using
naked eyes not aware of the risk they are exposing their eyes to in the long run.

Task:

As a learner of physics;

a) Explain the difference between total and partial eclipse.

b) Using illustrations, explain the differences between solar eclipse and
lunar eclipse.

In a certain experiment to investigate nature of light, the set up below was arranged.

9
 A concise approach to new curriculum physics questions by Buyinza David

a) State the property of light being investigated and explain its implications in daily life.
b) Explain what would happen when one of the cardboards is displaced slightly.

Item 20

We normally see the images of our faces when we look into the mirror. This is due to reflection
of light.

Task:

As the learner of physics;

a) State the laws of reflection of light and use them to find the glancing angle if
the angle of reflection is 350
b) Describe the nature of the images formed by plane mirrors.
c) State the real-life applications of plane mirrors.
d) With the aid ray diagrams, describe the differences between images
formed by plane mirrors and a pin hole camera.

Item 21

Two people stand in front of a cliff at an unknown distance between them as shown below.
 A concise approach to new curriculum physics questions by Buyinza David

The woman calls out the boy, she hears an echo of the sound she made after 4 seconds while the
boy hears the same echo 3.5 seconds later.

Task:

As a learner of physics;

a) Help these people to determine the distance between them.

b) Write a report about the factors that increase the rate of movement of sound.
c) Explain why it would be easier for the sound to travel from the girl to the
cliff at night than during the day

Item 22

While in your literature lesson, your teacher asks your friend to stand up and read for the class a
book of Oliver Twist, however your friend always tells your literature teacher that she is unable
to see the letters in the books and even when she sits near the board, she's unable to see but your
teacher and other fellow literature students think she's bewitched. On the s.4 leavers party, a boy
of height 120cm stands in front of a lens camera with a lens of focal length 40cm at a distance
160cm from camera.

Task

As a learner of physics,

by scale drawing

find the;

a) nature size and position of the image of the boy on the camera
b) explain to your fellow students and the literature teacher the cause of the
problem and the would-be possible solution to the above problem

Item 23

A certain student was puzzled that the shallow end of the swimming pool at his school
appeared to be about 1.5m deep when in the actual sense it was 2.0 m.

Use a ray diagram to illustrate student’s puzzle and explain why the swimming pool appeared
shallower than it is actually is.

Determine the refractive index of the water in the swimming pool at school
11
 A concise approach to new curriculum physics questions by Buyinza David
a) A barber was given a curved mirror of focal length 30 cm so that he
could use it as a shaving mirror in his salon.
b) Identify the type of curved mirror given to the barber and using a ray diagram
c) explain how the selected curved mirror is used as a shaving mirror.
d) State the properties of the image formed above?
e) Which type of curved mirror is suitable to be used as a side mirror and why?

Item 24

During a science project, learners are given two devices; a pin hole camera of length 50cm and a
concave mirror of focal length 50cm.

Tasks

As a learner of physics;

a) Help the students to determine which instrument forms a bigger image of a man of
height 1.8m standing 2m away from each of the instruments.
b) Explain the difference in the properties of the images formed by the two
instruments and identify the practical applications of the instruments.

Item 25

A barber was given a curved mirror of focal length 30 cm so that he could use it as a shaving
mirror in his saloon.

a) Identify the type of curved mirror given to the barber

b) Use a ray diagram to illustrate the use of the selected curved mirror as a
shaving mirror (05 scores)
c) What are the properties of the image formed above? (03 scores)

Item 26

Mr. Opolot a teacher of physics got challenges with his eyes and could not see properly; he was
advised to seek medical assistance from ophthalmologist. He was given spectacles with
converging lens of 20cm. while he was in class delivering strong thunder of wave length 2m
roared which resulted into the breaking of his spectacles and was unable to deliver the lesson
effectively that day. One of his students fixed a pencil of 10cm high at a distance of 60cm from
him. Hint: Speed of sound in air is 330ms-1 Task:

As a student of physics, lead a guided discussion that helps the

class to; Determine the;
 A concise approach to new curriculum physics questions by Buyinza David
a) Position
b) Height
c) Nature and magnification of the image that could be formed in his eyes.
d) Describe the power of his spectacles
e) Find the frequency of the thunder.

Item 27

One of your uncles wants to open a shop that deals with mirrors, and he has requested for your
advice on how best he can choose the mirrors for his shop which he just plans to open. Most
of the customers who buy mirrors need the following mirrors.

 Shaving mirrors and make up

mirrors.

 Saloon mirrors

 Side mirrors (rear view mirrors)

 Washroom / bathroom mirrors

 Security mirrors in supermarkets and parks.

Write down an explanation of how best you can help your uncle identify and choose the
mirrors wisely so that they can suit all his customer’s needs.

Item 28

One hot afternoon some learners walked along a tarmac road in the west ward direction to check
on a new swimming pool. On the road, they saw a speeding car at a distance and its engine
sounds kept on reducing as it moved further away. They also saw what looked like water near the
car; but the water disappeared when they reached the spot where they had seen it and it
reappeared to another spot ahead. Later on, the weather changed and there was a light drizzle
though the sun was still bright. In the Eastern direction, they observed a semi-circular
distribution of colours in the sky. They finally reached the swimming pool; however, the pool
attendant warned them to be careful when they are to use the swimming pool because it may
appear shallow when filled with water. The adventure ended in arguments because the learners
had different views about the observations and experiences, they had that day.

Task

Use your knowledge of physics to assist the learners to understand:

13
 A concise approach to new curriculum physics questions by Buyinza David
a) why the sounds they heard from the car kept on reducing?
b) the process that leads to what they observed on the tarmac road.
c) the process that leads to what they observed in the sky.
d) why swimming pool appears the way the attendant told them?

Item 29
During the music gala in a hall, one of the adjudicators observed the following;

On entering the stage, the colour of dress of one presenter changed from a yellow dress with red
dots to a red dress with black dots.

The sound from the nearest loud speaker reached him after 0.05s.

She kept on hearing voices of two people singing on stage, yet there was only one person on the
stage.

Hint: Speed of sound in air =320 ms-1

Task

Using the knowledge of Physics, help the adjudicator to understand;

a) Why the colour of the dress changed?

b) Why the sound was reaching her after 0.05s.
c) The origin of the second voice and how it can be minimized.

Item 30

A tycoon is to construct a first-class hotel and as he consulted from the technical personnel, the
following guidelines on facilities he wanted to set up were given;

The swimming pool should have a label of its depths at different points to avoid relying on a
deceptive look.

The multipurpose hall must have a soft wall or it must use curtains along the walls.

Each entrance should strictly have white lights as the inside of the hall may have other LED
lights for decoration.

The security personnel should have devices to check under the cars entering the hotel, as a way
of ensuring hotel security.

The tycoon is not knowledgeable about the importance of such guidelines in his upcoming
investment and is seeking for explanations.
 A concise approach to new curriculum physics questions by Buyinza David
Task

Using the knowledge of physics, help the business man understand;

a) the cause of deceptive look.

b) the reason behind multipurpose hall having a soft wall and curtains.
c) why the entrance must have white lights and how decoration on individuals
is attained from inside the hall.
d)
e) which kind of materials are needed in making the devices to be used while
checking under the cars entering the hotel?

Item 31
In a town, there is a woman who uses loud horn speakers to broadcast various information to the
community. She has received the following concerns from the members of her community;

Listeners at different locations have noticed a difference in time in which the sound reaches
them. People who are at far distances are unable to receive the information broadcast by the
speakers.

People are complaining about too much noise from the speakers, some of whom are not
interested at all in what is being broadcast. Because of those concerns, the town council
leadership has advised the woman to set up a radio broadcasting station and the broadcasting
authorities allocated her a radio frequency of 87.8 MHz

She is ready to take up the advice, only that she lacks enough knowledge to guide her more. Use:
Speed of light in air = 3 x 108 ms-1

Task:

Using your knowledge of Physics, assist the woman to;

a) differentiate between the type of waves produced by her current system and
those to be produced in the system proposed by the town council leadership.
b) understand why the new method of broadcasting will not cause a
problem of noise pollution.
c) understand why the new system of broadcasting is able to reach those who
are far away and they get the broadcast almost instantly.
d) determine wavelength of the waves used in broadcasting in the new system.

15
 A concise approach to new curriculum physics questions by Buyinza David
Item 32

One hot afternoon some learners walked along a tarmac road in the west ward direction to check
on a new swimming pool. On the road, they saw a speeding car at a distance and its engine
sounds kept on reducing as it moved further away. They also saw what looked like water near the
car; but the water disappeared when they reached the spot where they had seen it and it
reappeared to another spot ahead. Later on, the weather changed and there was a light drizzle
though the sun was still bright. In the Eastern direction, they observed a semi-circular
distribution of colours in the sky. They finally reached the swimming pool; however, the pool
attendant warned them to be careful when they are to use the swimming pool because it may
appear shallow when filled with water. The adventure ended in arguments because the learners
had different views about the observations and experiences, they had that day.

Task

Use your knowledge of physics to assist the learners to understand:

a) why the sounds they heard from the car kept on reducing?
b) the process that leads to what they observed on the tarmac road.
c) the process that leads to what they observed in the sky.
d) why swimming pool appears the way the attendant told them?

Item 33

During the music gala in a hall, one of the adjudicators observed the following;

On entering the stage, the colour of dress of one presenter changed from a yellow dress with red
dots to a red dress with black dots.

The sound from the nearest loud speaker reached him after 0.05s.
 A concise approach to new curriculum physics questions by Buyinza David
She kept on hearing voices of two people singing on stage, yet there was only one person on the
stage.

Hint: Speed of sound in air =320 ms-1

Task

Using the knowledge of Physics, help the adjudicator to understand;

a) Why the colour of the dress changed?

b) Why the sound was reaching her after 0.05s.
c) The origin of the second voice and how it can be minimized.

Item 34

A foreign investor secured a space in rural set-up where human settlement has been set-up to set-up a steel
rolling industry associated with production of very sharp sound that human ear cannot withstand. On
wearing recommended eye protective mirror, an erect, virtual and twice in size image is observed 60cm
from the mirror.

Task

As a physics student

a) Identify the type of sound waves produced and state their practical use to man

b) Suggest measures that can be used to minimise their negative effects

c) Identify the type of mirror recommended with a support

d) How far, from the metal surface should the engineer cutting, bend

Item 35

A night swimming pool cleaner accidentally dropped his torch into the pool while on a duty after a heavy
rain that left the whole place logged with storm water and attempted to retrieve it as he was seeing light from
the torch appearing closer to the water surface. Unfortunately, he fell into the water in an attempt to remove
the torch as his hand couldn’t reach the bottom of the pool. He screamed for help when about to drown in
water but was surprised to hear his voice after drowning in water 0.5s later. When he got out of the water he
tried to understand why he heard his own voice by shouting again but this time round the sound came little a
bit later than while he had drowned in the water and this was 0.16s later. This made him more confused.

Supporting information

17
 A concise approach to new curriculum physics questions by Buyinza David
Sound travels at different rates in air and water

The swimming pool is surrounded with a perimeter wall at a distance of 54m in all directions

The distance from where he fell to the tall boundary wall is 50 m

Task

As a student of physics, help the cleaner

a) Understand why he was unable to reach his phone with his hand, even though it seemed close to the
water surface
b) Understand why he heard himself at different time intervals when he was screaming
c) Explain how he was able to hear himself when he had drowned
d) Compare the rate at which sound travels in air and water

Item 36

Consider your school organizing an annual music, dance and drama (MDD) event. To accommodate the
large number of spectators, the MDD committee has been tasked with building a stage in school compound.
The MDD stage is to be positioned adjacent to the main hall, to minimize interference of echoes. To ensure
optimal stage location, the committee is advised to use a parabolic mirror to focus a laser beam from the
proposed stage position to the main hall wall to check for echoes. Additionally, they need to decorate the
stage with unique sources of light. However, the committee members are not familiar with some of these
tasks and seek your help

Hint

Speed of sound in air is 330ms-1

During the testing, sound from the laser source took 0.16s to make one round trip

Stage has been decorated with a source of red light

Task

As a physics student help the committee members to understand

How echoes are formed and why it’s important to avoid them during such performance

To avoid interference by echoes, guide the committee on whether the selected position is a perfect spot for
the image

Explain why a laser beam is preferred to the ordinary light in determining distance for the most appropriate
echo free stage position
 A concise approach to new curriculum physics questions by Buyinza David
Describe the setup of a parabolic mirror and how it is used to focus a laser beam

Explain how a yellow dress with blue spots will appear while on stage when red light is shone on it

Item 37

During a visit to a laboratory, students observed a ripple tank of depth 50cm filled with water where
modifications had been made to create a shallow end of depth 30cm. A circular rod vibrating at 40 Hz from
the shallow end is made to produce ripples. To their surprise, the spacing between successive troughs
changed from 5cm to 2.5cm, the velocity of the ripples changes and are distorted when they strike the tank
walls.

A stick that was in the tank appeared bent which scared the students.

Task

Use your knowledge of physics to explain:

(a) Why there was a change in the velocity of the ripples.

(b) How to reduce the distortion of the waves.

(c) To the students because the stick appears bent.

EARTH AND SPACE PHYSICS

Item 1

On a national radio station, it was announced that in one of the small towns of Pakwach in
Uganda, residents observed the moon block the sun completely for about seven and a half
minutes, it was further communicated that in most parts of the country annual precipitation
occurred, fresh water quality improved and vegetation started growing substantially.

Task:

As a student of physics, help the listeners to understand:

a) The possibility of the moon blocking the sun’s light

b) The occurrence of annual precipitation, improvement on fresh water quality and
vegetation growth.
c) How an event in one place can be communicated live to listeners in different parts
of the country.

19
 A concise approach to new curriculum physics questions by Buyinza David
Item 2

In a certain country, a Television (TV) reporter was reporting live near the ocean about the high
tides during night time. Viewers in another country were watching the live broadcast of the news
bulletin during day time. The viewers wondered how it could be day and night at the same time,
and how the event in one country could be watched live on TV in another country.

Task

Using your knowledge of physics to help the viewers to understand;

a) the possibility of it being day in one place and night in another place.
b) the occurrence of high ocean tides.
c) how an event in one place can be broadcast live in
another country.

Item 3

An article in the newspaper gave information that on 2ndDecember 2022, Ugandan engineers
with the

help of Japanese engineers launched a satellite. The literature teacher who picked interest in the
article

found new words like artificial and natural satellites. He developed a number of unanswered
questions

which could be answered by a physics learner like you.

(a) Explain the difference between the two types of satellites in the article.
(b) With reasons, justify why Uganda should spend all that much money to
launch its own satellite.
(c) Incase Uganda is to develop a super rocket capable of reaching different
planets. List with reasons the planets It can land on and planets it cannot land on.

Item 4

In some part of Uganda, people have been ordered to vacate their area and relocate to other parts
of the country in anticipation of heavy rains in the coming months that are likely to cause
flooding and landslides. The relocation process will be broadcasted live on television to ensure
transparency in the whole process. The local council (LC) authorities have been requested to
sensitize the people about this issue. However, the LC authorities are experiencing challenges in
explaining to the people.
 A concise approach to new curriculum physics questions by Buyinza David
a) Why rains were experienced in the area while other parts are experiencing dry seasons?
b) How is it possible that weather patterns can be accurately predicted before they occur?
c) How a live broadcast is possible in this area?

Item 5
The science club at a secondary school as initiated a national science literacy campaign. As part of this
effort, they are hosting a series of outreaches aimed at primary school pupils to foster a better understanding
of astrophysics and its relevance to everyday life. the focus of their discussions will include energy
production in stars, the importance the suns energy, the variation in stars colors, the life cycle of stars and
the importance of space exploration

Task

As a physics student, you have been requested by the school science club to deliver in one of the outreaches
to primary school pupils. Your task is to educate them on

a) How the sun produces energy needed for life to survive

b) The variation in colour and brightness of stars in a milky way in terms of their size and distance from
the earth
c) The different stages in the life cycle of a star
d) The purpose of the international space station and its role in space exploration

Item 6

On a certain day at around 1:30pm while in the dining hall, learners watched heavy fog-rains and
floods being experienced in a certain outside country on an international T.V live channel. To
worsen matters, the floods were happening at night and this risked many natives as many of them
were ambushed while asleep. Learners wondered how it would be night and seriously raining in
an area yet it was day and the Sun was highly shinning at that time in their school.

Task:

As a physics learner help the learners clear their queries about;

a) Occurrence of the floods in one area yet it was shining in their school at same time.
b) Why it was night in that outside country yet it was day-time in their area?
How T.V signals broadcast from where the floods were happening
reached them.

21
 A concise approach to new curriculum physics questions by Buyinza David
Item 7
In 2014, Brazil hosted FIFA world cup where different countries participated in the tournament. Some
countries such as Uganda did not qualify for the tournament and hence had to watch the matches live on TV
screens. In one of the games, it was evident that it was day time in Brazil yet in Uganda it was night time
which puzzled John and as he was watching the game live on TV, during the same period of world cup
tournament it was winter in Brazil which affected some of the participant nations in the tournament

More support information

At Johns home there was a satellite DSTV dish

Task

Using your knowledge of space physics

a) Help john understand the cause of night in one country for which it is day time in another country
b) Explain the cause of variations in seasons
c) Explain how communication was possible in this situation

Item 8

S.3 and S.4 students of a certain school were to have a motion (debate) about time durations of a day, night
and seasons of a year normally experienced in their lives. This motion was to be presented to parents most of
whom are peasants on the visitation day

In the debate, one presenter argued that ocean tides are the causes of these durations. Another learner
supplemented that ocean tides and drought are caused by artificial satellites placed in space by powerful
countries like Russia.

A parent who had attended also supplemented that seasons are brought about by the motion of the planets
about the sun and this distorts climatic conditions

The audience got confused of the arguments. a learner from the audience raised an inquiry if there can be
means of getting some information about these weather changes and planets

Chairperson tasked each participant to make more research so that they can have clear information in the
next presentation

Task
 A concise approach to new curriculum physics questions by Buyinza David
As a learner of physics, help the audience to

a) Understand about time duration of the day, night and year

b) Explain the occurrence of seasons and ocean tides
c) Know what artificial satellites are and their role in everyday life

Item 9

Recently your female friend enrolled in an Astrophysics course in one of the outside countries. After a few
days of settling in, she called her parents in Uganda by 9am local time in that country. However, in Uganda
it was 8pm. Her parents had just received the news that the crescent moon had been sighted using the
satellite communication indicating the start of fasting of the holy month. During the conversation she
mentioned that her first lecture was about life cycle of a star and were also curious about the significant time
difference between the two countries. The parents seek your explanation about these events

Task

As a physics student, help the parents to understand

a) What causes the differences in time such that in the country of study is 9am (day time) and in
Uganda is 8pm (night time)
b) The crescent moon sighted is believed to have phases, explain the phases regarding the new moon to
full moon
c) Briefly describe the life cycle of a star
d) During a satellite communication, a combination of logic gates is used to encode and decode
messages. For example, an OR gate combines two signals, A and B. If the output of the OR gate is
true, the satellite transmits a signal back to earth otherwise, it does not. Basing on the conditions
described, explain whether the satellite will transmit signals back to earth if A is false (logic 0) and is
true (Logic 1)

Hint Include a truth table for the OR gate in your response

Item 10

A child went out of the house at around 8:30pm and realized that security lights were off. The
child saw glittering substances in the space and wondered why the clouds were so much
glittering. While still wondering, the child heard a person tip-toe and rushed to the corridor with
light switches to switch on. Unfortunately, the corridor was closed by parents who had
mistakenly gone with the keys and was not yet back. The person knocked on the gate but the

23
 A concise approach to new curriculum physics questions by Buyinza David
child was challenged whether the parent had come and had to open or the person knocking was a
thief.

Later the parent came, and when the child narrated, the parent said the glittering substances were
artificial satellites in the international Space Station (ISS).

Task:

As a physics learner, using the knowledge of space physics and digital electronics, help the child
and parent:

a) Understand more types of those identified satellites and why they exist there without
falling.

b) Solve the problem of operation of security lights.

Item 11

One of the most misunderstood branches of physics for years has been space physics
(Astronomy).

Some of the examples of such misunderstandings include the following.

•While watching the world cup which took place in Brazil in 2014 at 9:00 pm East African
time, the football fans watching the game in E. Africa realized that it was still day time in
Brazil, some of them were puzzled by this.

•The NASA (National Aeronautic and Spaced Administration) tells us that the only planet that
supports life is earth.

TASK:

How can you explain the above statements in case one of your classmates, siblings or friends
wants to know about the astronomical events in order to promote deeper understanding of
physics in the school and community at large?

Item 12

The solar system is composed of big, small and much smaller objects including planets. All
planets

move around the sun in elliptical paths. The motion is both rotational and revolution. Rotation
motion
 A concise approach to new curriculum physics questions by Buyinza David
involves the planets spinning about a fixed axis and revolution motion involves planet moving
around the sun.

TASK:

a) Identify the other components of the solar system. (3 scores)

b) Which name is given to the path in which planets move? (1 score)
c) Draw diagrams to show rotational motion and revolution motion. (2 scores)

Item 13

People in a certain country were surprised one day at about noon it became dark as if it was night. Some
people told stories that the moon was fighting the sun others said God was annoyed. Then a certain man
among the people called a friend in another country using his mobile phone to find out whether they were
also experiencing the same.

The friend informed the man that for them, they were in night time and it was approaching 11:00pm. People
were observing the man calling and communicating to someone in another country. They wondered how one
in one country could communicate with anther in another country while the man was also wondering how it
could be day time and night time in different places. After a short time, the darkness cleared and the day
became normal

Task

Use the knowledge of physics,

a) Help the people in that country understand the possibility of darkness to fall on earth in some parts
during day for a short time

b) Help the man understand why it is day in one part of the earth and at the same time it is night in
another part

c) Help the people in that country understand how one in one country can communicate to another one
in another country

Item 14

some regions in Uganda are affected by the changes in seasons that sometimes may lead to famine.
Accordingly, the people in Uganda have been demanding for solutions from the government to ensure
famine does not occur any more In November 2022, the government launched a satellite into the lower Earth
orbit through support of the international space station (ISS). A number of people criticized the move by the

25
 A concise approach to new curriculum physics questions by Buyinza David
government to launch the satellite into space, claiming that the satellite will not solve the problem of famine
in Uganda

Task

a) As a physics student,

b) Help the public to understand the occurrence of seasons

c) Make the people understand and appreciate the reason why the government took the above move

Item 15

James a 15-year-old the day when Muslims stopped fasting observed a small curved object in space that
emitted light at night and after a number of days it became bigger, circular and emitted light of much more
intensity. One day when the object could not be seen, he observed tinny bodies in space that seemed to move
closer and at the same time appeared to recede from him. When he went back to the house there was a live
broadcast of a football match in Spain on their TV, and on changing the TV channel to National
Geographical Science, he saw the pictures in the figure below

Hint

Figure 2 (b) resembles what James saw in space during the days the bright object had disappeared

Task

As a student of physics ready to explore the wonders of space physics,

Help James explain why

 A concise approach to new curriculum physics questions by Buyinza David
a) The object changed the size and its brightness and eventually disappeared as days increased from the
first day Muslims stopped fasting
b) Tinny shinny bodies appear to move closer and recede from him at the same time
c) Explain to James
d) How it is possible to be day time in Spain and night time in his place
e) How the football in Spain and the pictures in figure 2 (a) and (b) are ably seen on his Tv
f) Briefly describe one theory that explains the existence of objects seen in figure 2 (b)

Item 16

Learners of a certain school were watching a documentary video by NASA who had recently launched the
stellar surveyor mission to the ISS to study the solar system, life cycle of stars, as well as energy they
evolve. The crew in the mission was equipped with the Hubble Telescope and other equipment to collect
data. The narrator said that the mission marked a significant milestone in space exploration, demonstrating
the ISS’s potential as a platform for advanced space exploration. After the lesson, a learner was asked to
write an article about space mission so that it can be published in the school magazine but she could not
provide enough information.

Task

As a learner of physics, help the learner come up with a write up to be published in the school magazine
about the explanation of the

a) Components of the solar system

b) Life cycle of stars
c) Relevancy of the Hubble telescope and the ISS in the mission

Item 17

In every year, there are various seasons which all people rely on to carry out different activities.
At the beginning of a year here in Uganda, many people complain about too much sunshine
wondering where the sun gets such too much energy from. Such people even wished the sun to
die to have peace during the day and others prefer endless nights so that they don’t have to deal
with the sun. However, some people attributed the sun as the major source of energy on the
earth.

Task:

As a physics student explain to the people;

a) Where the sun sources its much energy from.

27
 A concise approach to new curriculum physics questions by Buyinza David
b) Why some people attribute the sun as the major source of energy on the earth.
c) About occurrence of various seasons and the likely stages that an average star like the
sun may undergo to satisfy the wish of some people.

Item 17

As a physics student, you are tasked to design a home security light control circuit, the light
should be activated by either manually pressing a switch or automatically by a light sensor. The
sensor works as follows; when there is sunlight outside, it switches of the light but when there is
darkness, it switches on the light. Draw a logic circuit diagram and a truth table for all the
possible operations.

Item 18

A greenhouse farmer has two sensors in his green house; a temperature sensor and a humidity
sensor. The plants in his greenhouse can’t give good yields if the temperatures are above 35 or
if the humidity is high. He wants an alarm to be sounded if the plants are not having appropriate
conditions for giving good yields. Using logic circuits, describe how this can be achieved.

Item 19.

In a certain country, a Television (TV) reporter was reporting live near the ocean about the high
tides during night time. Viewers in another country were watching the live broadcast of the news
bulletin during day time. The viewers wondered how it could be day and night at the same time,
and how the event in one country could be watched live on TV in another country.

Task

Using your knowledge of physics, help the viewers to understand;

a) the possibility of it being day in one place and night in another place.
b) the occurrence of high ocean tides.
c) how an event in one place can be broadcast live in another country.

Item 20
One of the most important components of our solar system is the sun. Another important
component of our solar systems are the big masses called planets.

a) Name all the planets found in our solar system.

b) Identify the planet that sustains life in our solar system.

c) How are the times and seasons of the year explained on the planet mentioned in (ii) above?
 A concise approach to new curriculum physics questions by Buyinza David
d) Explain the statement “the sun has a life cycle”.

Item 21

On November 7th 2022, Uganda launched its first satellite named Pearl Africa Sat-I into space
with the help of National Aeronautics and Space Administration (NASA). The purpose of the
mission was to study weather patterns. Students of physics were availed with data collected over
a certain of time and they noticed the following while some places were having day time. Other
places were having night time. Various places were having different seasons.

Task:

As a learner of physics

a) Explain why some places had daytime while it was night time at other places.
b) Explain why different places had weather patterns and how world- wide communication
is made possible through satellites.

Item 22

One of the most important components of our solar system is the sun. Mathias’ father was called
by his son who stays in Canada at exactly 8pm. While communicating using video chart he
realized Matthias was still walking in sunlight in streets of Canada. This confused the father and
asked why it was like that Uganda being night and Canada still in day light. Mathias laughed and
told his dad not to even get surprised and added that there are other important components of our
solar system with big masses called planets. The dad got confused the more.

Task

As a sibling to Matthias and a learner of physics, help your dad to;

a) Know what is meant by the planet and identify all the planets found in the solar system.
b) Differentiate between the smallest and largest planet in the solar system
c) Identify the planet that sustains life in our solar system and greatest importance of the
sun to the people.
d) Realize what causes the difference between a day and night.

Item 23

One of the most misunderstood branches of physics for many years has been space physics
(Astronomy). Some of the examples of such misunderstandings include the following.

29
 A concise approach to new curriculum physics questions by Buyinza David
The Catholic church at one time thought that other heavenly bodies, including the sun, orbited
around the earth, rather than the earth. This was the problem that Catholic hierarchy had with
Galileo. For example, the Church tried and arrested Galileo Galilei for supporting Sun-centered
view of the universe.

While watching the world cup which took place in Brazil in 2014 at 9pm East African time, the
football fans watching the game in East Africa realized that it was still daytime in Brazil, some of
them were puzzled by this?

While it snows (winter) in most European countries in December around Christmas season,
the people in East Africa have never seen any snow fall in East Africa and some of them
wondered why it is this way?

Task

How can you explain the above in case one of your classmates, siblings or friends is among those
who need enlightenment about these astronomical events in order to promote deeper
understanding of physics in the school and community at large?

Item 24

As a man in Uganda was watching an educative TV show at 11:00 am, the program was
interrupted to bring a live broadcast of some educative night time events in South Mexico. The
live broadcast showed some children that who were viewing a dark sky on a cloudless, clear
night. The dark sky had greyish areas and many bright twinkling spots of different extents of
brightness and colors. Some of the bright spots appeared to be moving. The TV presenter
reported that unlike night time, there was only one outstanding bright object in the sky during day
time and that it is part of a continuously evolving universe. The man was unable to understand
this TV production and wished to have a clear explanation.

Task:

As physics student, help the man to understand:

a) what the observed grey areas that the learners saw represent.
b) what the artificial bright spots represent and their significance in the universe.
c) why there are outstanding bright objects that the TV presenter mentioned, and
their significance in the universe.

why there existed:

a) different levels of brightness of the bright spots.

 A concise approach to new curriculum physics questions by Buyinza David
b) differences in colour of the bright spots.

Item 25

In some southern part of South Africa, people were ordered to vacate their areas and relocate to
other parts of the country in anticipation of the heavy rains in the coming months, that are likely
to cause flooding and landslides. The Local authorities have been requested by the Ministry of
Disaster Preparedness to sensitize the people about the issues. However, they are finding
difficulties in explaining to the people: -

Why rains will be experienced in their area while other parts of the continent are experiencing
dry season.

How it is possible to predict accurately weather patterns before they occur.

Why there are two seasons threatening them with high rainfall in a period of just a year.

Task

As a student of physics, help the Local authorities to understand: -

a) The variations in seasons as realized by the locals at the same time of the year.
b) How the weather is always accurately predicted before it happens.
c) Why the community is experiencing that challenge twice in the same year.

Item 26

In recent times Uganda joined a number of countries that have launched an artificial satellite.
When the satellite is in orbit, the sun is the major source energy needed for operation of devices
on the satellite. Some Ugandans think that the government is wasting resources in such activities
and are planning to make a protest. You have been invited to make a presentation that can answer
these Ugandans.

Task:

In your presentation:

a) Explain why it is important for a country to have that type of technology.

b) why that object is called “artificial”.
c) Inform them about other bodies that are kept in this type of motion.
d) Explain why such bodies have this kind of motion.
e) Explain how the major source of energy produces energy.

31
 A concise approach to new curriculum physics questions by Buyinza David
f) Explain the other roles of the major source of energy, on earth.

Item 27

An elder in a certain village was narrating to his family members his experience of a visit to
London. He said that in London, day time was longer than night time with 16 hours of day and 8
hours of night, this was unique to family. He also added that stars were rare organisms that died
at day time and resurrected at night. Furthermore, he stated that the shape of the moon kept
changing over a month’s cycle. The family members, in comparison, said that some of the elder’s
experiences were equally observed in their village but unfortunately did not understand these
occurrences.

Task

As a student of physics, help the elder and his family to understand;

a) how the unique observation in London came about.

b) the observation of stars at day time and night time.
c) why the shape of the moon keeps on changing over that period

Item 28

As a man in Uganda was watching an educative TV show at 11:00 am, the program was
interrupted to bring a live broadcast of some educative night time events in South Mexico. The
live broadcast showed some children that who were viewing a dark sky on a cloudless, clear
night. The dark sky had greyish areas and many bright twinkling spots of different extents of
brightness and colors. Some of the bright spots appeared to be moving. The TV presenter
reported that unlike night time, there was only one outstanding bright object in the sky during day
time and that it is part of a continuously evolving universe. The man was unable to understand
this TV production and wished to have a clear explanation.

Task:
 A concise approach to new curriculum physics questions by Buyinza David
As physics student, help the man to understand:

a) what the observed grey areas that the learners saw represent.
b) what the artificial bright spots represent and their significance in the universe.
c) there are outstanding bright objects that the TV presenter mentioned, and
their significance in the universe.

why there existed:

a) different levels of brightness of the bright spots.

b) differences in color of the bright spots.

Item 29

After research work, your group has presented the following article that was collected from a
journal on nuclear science….

At the end of your presentation, some classmates have not understood the ideas in it, and have
requested you on behalf of the group to give them more details.

Task

As a learner of Physics assist them by:

a) explaining how the discoveries on radioactivity have played a great role in enhancing
the development different sectors.
b) explaining how harmful the discoveries can be, in the field of medicine.
33
 A concise approach to new curriculum physics questions by Buyinza David
c) showing, using a well-balanced equation, how uranium reduced to thorium.
d) determining the time taken by the uranium isotope to reduce to half its original size.

Item 30

In some southern part of South Africa, people were ordered to vacate their areas and relocate to
other parts of the country in anticipation of the heavy rains in the coming months, that are likely
to cause flooding and landslides. The Local authorities have been requested by the Ministry of
Disaster Preparedness to sensitize the people about the issues. However, they are finding
difficulties in explaining to the people: -

Why rains will be experienced in their area while other parts of the continent are experiencing
dry season.

How it is possible to predict accurately weather patterns before they occur.

Why there are two seasons threatening them with high rainfall in a period of just a year.

Task

As a student of physics, help the Local authorities to understand: -

a) The variations in seasons as realized by the locals at the same time of the year.
b) How the weather is always accurately predicted before it happens?
c) Why the community is experiencing that challenge twice in the same year.

Item 31

In recent times Uganda joined a number of countries that have launched an artificial satellite.
When the satellite is in orbit, the sun is the major source energy needed for operation of devices
on the satellite. Some Ugandans think that the government is wasting resources in such activities
and are planning to make a protest. You have been invited to make a presentation that can answer
these Ugandans.

Task:

In your presentation:

Explain

a) why it is important for a country to have that type of technology.

b) why that object is called “artificial”.
c) Inform them about other bodies that are kept in this type of motion.
d) Explain why such bodies have this kind of motion.
 A concise approach to new curriculum physics questions by Buyinza David
e) Explain how the major source of energy produces energy.
f) Explain the other roles of the major source of energy, on earth.

Item 32

You are tasked with designing a simple burglar alarm system for a small storage facility. The
system uses two types of sensors as inputs and is connected to a single alarm light that turns on
when a potential intrusion is detected. The two inputs are:

Door Sensor (D): This sensor is placed on the door and sends a signal (1) if the door is
opened and 0if the door is closed.

Motion Sensor (M): This sensor detects movement within the storage room. It sends a
signal (1) when motion is detected and 0when there is no motion.

The burglar alarm system should activate (turn on the alarm light) only if the following
conditions are met:

Condition 1: The door is opened, and there is motion detected inside the room (indicating
an unauthorized entry).

Condition 2: There is motion detected inside the room, but the door is closed (indicating
someone might be inside without having used the door, possibly breaking in through a
window or another unmonitored entry).

Task:

a) Determine the appropriate logic gate configuration to achieve the desired output for
the burglar alarm system. Specify which logic gates you would use and how you
would connect the inputs (D and M) to these gates to produce the correct output for the
alarm light (A).
b) Construct a truth table for the inputs (Door Sensor -D, Motion Sensor -M) and the
output (Alarm -A). The truth table should represent all possible combinations of the
inputs and the corresponding output state of the alarm light.
c) Provide a clear explanation of why you chose the specific logic gates and how they
fulfill the requirements of the burglar alarm system based on the conditions provided.

Item 33

An elder in a certain village was narrating to his family members his experience of a visit to
London. He said that in London, day time was longer than night time with 16 hours of day and 8

35
 A concise approach to new curriculum physics questions by Buyinza David
hours of night, this was unique to family. He also added that stars were rare organisms that died
at day time and resurrected at night. Furthermore, he stated that the shape of the moon kept
changing over a month’s cycle.

The family members, in comparison, said that some of the elder’s experiences were equally
observed in their village but unfortunately did not understand these occurrences.

Task

As a student of physics, help the elder and his family to understand;

a) how the unique observation in London came about?

b) the observation of stars at day time and night time.
c) why the shape of the moon keeps on changing over that period

Item 34

A football match was being broadcast live from country A at 4:00pm. Viewers from another
country B was watching this match live at 8:00pm with their television (TV) screen outside the
house. It was bright like day because of the Moon. They started arguing about the Moon's size
where one member posed a question asking why the moon Is different in size always. This
silenced everyone. The beauty of stars also caught the Attention of some viewers. They started
wondering why some stars look brighter than others.

Task

Using your knowledge of physics to help the viewers to understand;

a) Why the moon is different in size throughout its cycle, naming each of the distinct
Sizes and how long this cycle takes. (08scores)
b) The reason for the different brightness of the stars in the night sky. (04marks)
c) How football can be broadcast live in country B; and the possibility of it being
4pm In country A and 8pm in another country B.

Item 35

A man who stays in an area with a view of the ocean requested his mother to pay him a visit in Canada. On
her arrival at her son’s home, it was noon but her watch set to the Ugandan time read 8:00pm. On looking
through the window, she also noticed very high waves in the ocean which was different from the photos that
were sent to her.

The mother called you to confirm if it was indeed night in Uganda while it was day time in Canada

Task
 A concise approach to new curriculum physics questions by Buyinza David
a) As a physics student, explain to the mother
b) Why it was night in Uganda and day time in Canada
c) The cause of high waves in the sea
d) How a person in Canada is able to make a phone call to Uganda

Item 36

In a certain year, Eid-l-aduha celebration day had been spotted for Tuesday 14th but to the people’s surprise,
the date of the Eid changed to Monday 13th. This affected mainly the business community. This true because
Muslims celebrate their Eid upon sighting of the moon. As a physics student, help and explain to the public
and business community why

The date had to be changed and what caused it to change

Jupiter in our solar system has 12 earth years as its period around the sun with about 10 hours of its day it
also has about 95 named moons yet the earth has only one moon and its day is 24 hours

Using your knowledge help to explain this to the locals who are doubting

Students saw a shooting star in the sky and started making their wishes little did they know that their wishes
are not connected to the shooting star.

Using your knowledge of physics help and explain to the students how a shooting star comes about

Item 37

Over a period of six months, the learners in Senior Two observed the following:

• The length of day and night kept varying on different days.

• The shape of the moon kept changing in a 1-month cycle.

• Different areas on earth had different weather.

However, the students cannot explain these phenomena and have approached you for help.

Task
As a physics learner, help them understand;

(a) Why the length of daytime and nighttime varies.

(b) Why the shape of the moon varies in a 1month cycle.

(c) The variation in weather between the various places.

37
 A concise approach to new curriculum physics questions by Buyinza David
NUCLEAR PROCESSES, ATOMIC MODELS
Item 1

With the intention of producing electricity by 2030, the Ugandan government is preparing to
construct its first nuclear power station. The goal of this large-scale initiative is to meet the
nation's increasing energy needs in a sustainable manner while lowering its dependency on fossil
fuels. However, due to worries about the safety of nuclear power, there has been a lot of public
criticism. Many people are unaware of the various benefits of nuclear energy and are concerned
about the possibility of explosions if energy production is not controlled, the impact of
background radiation and long-term risks posed by radioactive waste with long half-lives.

Task: A well-known local radio station has invited you as physics student to address the public's
worries and provide an explanation of the science behind nuclear energy production in a nuclear
reactor in a controlled way.

Item 2

The government has discovered a precious and rare mineral in a certain part of the country. A team of men
picked samples and kept them in a store of one of the hospitals where photographic plates are also stored.
The mineral was checked on regularly and they made the following observations;

All photographic plates had darkened.

Its mass reduced spontaneously with time as shown below

Mass 200 150 70 35 25

(g)

Time 0 4 16 28 30
(days)

As a physics learner,

(a) Support the view that the mineral is radioactive.

(b) Use the graph to estimate its half-life
(c) Explain the best way of storing this rare mineral.
(d) What are the dangers of exposing this mineral to the public

Item 3
 A concise approach to new curriculum physics questions by Buyinza David
In a research laboratory, scientists are investigating the properties of atoms and the behaviour of
electromagnetic radiation. Here are some observations and findings from their experiments:

Observation 1: scientists analyse the composition of different compounds. They found that regardless of the
compound, elements combine in simple, whole number ratios by mass, consistent with Dalton’s atomic
theory

Observation 2: using a particle accelerator, they shoot alpha particles at a thin gold foil. They observe that
most alpha particles pass through the foil undeflected, but a few are deflected at large angles.

Observation 3: scientists shine ultraviolet light on a metal surface and observe the emission of electrons.

Task: As a learner of Physics;

(a) discuss Dalton’s postulates; and how does the findings in Observation 1 support
Dalton’s postulates.

(b) explain how the experiment in observation 2 provides evidence for Rutherford’s atomic model and
what conclusions can be drawn about the structure of the atom from this observation.

(c) describe the phenomenon in Observation 3. Why do you think the production of x-rays is the inverse
of the phenomenon in Observation 3?

Item 4

In a certain trading centre, the pressure of water in taps have seriously reduced and in some parts of the
town, water is completely not there. This has worried locals around that town. Local authorities have
been consulted to check whether there is any problem with underground water supply system in pipes
before the issue is reported for further management.

Task.
39
 A concise approach to new curriculum physics questions by Buyinza David
As a learner of physics;

a) Help the local authorities to choose from the table the appropriate materials they would
use to report the issue of low pressure in the taps.
b) Sensitize locals of the town the likely method to detect the location of leakage in pipes
with reasons.

Item 5

A factory that manufactures aluminium plates intends to put up a system that monitors the
different thicknesses of the sheets according to customer specifications. The scientist advised
that a radioisotope emitting beta particles can be used during some time when its activity
doesn’t reduce to a count rate of the same value as the background radiation. Table 1 shows
the decay process of the radioisotope and other materials available for use in the process of
monitoring thicknesses

The factory owner doesn’t know:

I. Whether this radioisotope is appropriate for use.

II. How the process of thickness monitoring is
done.
III. Background radiation and its causes.
IV. How many days this sample will work before it is replaced by another one.
V. The owner is unaware of the safety measures the factory needs to take to
mitigate the hazards associated with handling radioactive materials.
 A concise approach to new curriculum physics questions by Buyinza David
Task: As a student of physics, help the owner of the factory with all the necessary
information in regard to the challenges being faced.

Item 6

An underground water pipe in the school compound cracked and water gradually
leaks into the surrounding ground. The school laboratory is well stocked with various
radioactive materials. The school compound prefect tries to locate an actual point
where water leaks but fails. The school hires a technician who introduced a
radioactive isotope of half-life 6hours of 8g from the laboratory into the water supply
and the water that leaks from the crack is radioactive.

Hint: Assume the safety desired level of radiation is 6.25%

Task:

As a student of physics;

a) Explain the type of radiation that was emitted by the isotope for the leak
to be detected.
b) Explain to the compound prefect why an isotope of half-life 6 hours is
suitable for use.
c) Write a message to sensitize the members of the school about the
risks associated with radioactive materials in the school laboratory
and how such materials should be handled.
d) How long shall it take for the water to be ready for use again?

Item 7

A group of students visited the nuclear power plant and they were blocked from entrance due to
an accident that had occurred and several operators were exposed to radiation. Only emergency
cars were allowed to enter to transport the operators to the hospital to undergo medical
examination, including x-ray scans to assess any potential radiation related injuries. Students
wondered how harmful radiations were. It became hard for them to understand even how the
power plant could generate electricity after being told at the entrance that the plant was the only

41
 A concise approach to new curriculum physics questions by Buyinza David
source of electricity in that area. If the plant’ s radiation monitoring system detects a background
radiation level of 30 counts per minute, and when the radioactive source is placed in front of the
radiation detector, the reading on the detector is 550 counts per minute and the source has a half-
life of 25 minutes.

Hint: The power plant will be safe for use if the detector reads 95 counts per minute.

Task

As a student of physics;

a) Advise the Power plant team leader on how long they had to wait for the power plant to
be safe for use.

b) Help the students to understand;

c) the relevant nuclear process at the power plant

d) Understand type of radiations emitted at the power plant and their

properties

e) How are the emitted radiations different from x-rays?

f) Assist learners to appreciate that indeed the guide was right to stop them and explain how
the operators managed to be there always.

Item 8

In a certain hospital, a patient has come in with suspected broken bone in their arm, and another
patient is scheduled for a dental examination. Your x-ray machine produces electromagnetic
waves with a frequency of 𝟔×𝟏𝟎 18𝑯𝒛. Your supervisor asks you to;

I. Take an X-ray image of the patient’s arm to confirm the bone fracture diagnosis

II. Take a dental X-ray to examine the patient’s teeth and jaw alignment

Hint

Wavelength of x- rays 5×10-11m 5×10-10m 5×10-9m

Image resolution High Medium Low

Task: As a learner of physics;

a) Comment on the resolution of the image of patients arm and bone fracture.
 A concise approach to new curriculum physics questions by Buyinza David
b) Explain how the frequency and wavelength relate to the penetrating power of the x-rays
and how this affects your choice of settings for the arm and dental exams

c) Suggest possible precautions taken while dealing with x-ray

machines.

Item 9

A certain town experienced an atomic bomb blast, many people were killed in the incidence and others
survived with severe injuries, the government advised those survived to re-locate to other places of the
country because this village was not safe for them. The scientist carried out a scientific investigation using
detectors of radiations and found out that the environment was still radioactive as shown in the table below

Time (days) 0 22 42 62 82 102 122 142 162

Count rate (min-1) 106 83 66 56 47 36 31 26 15

The scientists recommended that the environment will be safe for use again when obtained half-
life value is less than 60 days and they will need like 1 year (365 days) for the environment to be
free from radioactive wastes and materials.

Task: As a student of physics, use your knowledge to:

a) Help the people to know the value of half-life and advise them accordingly.

b) Sensitize the people about the risk associated with radioactive materials and how they
should be handled

c) Help the people to understand the value of number of neutrons of a nuclide Y formed
when a radioactive substance X of mass number 208 and atomic number 104 decays by
emitting 3 alpha particles, 4 beta particles and gamma rays to form a nuclide Y.

Item 10

In a certain town, people are concerned about the waste disposal from the factory into nearby lake
which is their source of water for home use. They raised this issue to the chairperson Local
Council 1 (LC1) who directed the management of the factory to stop disposing waste into the
lake. A scientist was contacted to investigate the presence of radioactive material in the water.
The scientist found out that the water was indeed radioactive as shown in table 1.

43
 A concise approach to new curriculum physics questions by Buyinza David
Time/days 0 5 10 15 20 25 30

Activity/counts
1200 740 440 260 160 90 60
per minute

Although the water from the lake remains radioactive for a long time, the scientist recommended
that water will be safe for use again when the activity is less than 38 counts per minute.

Task:

As a student of physics;

a) Advise the chairperson LC1 about the time the community will wait for the water to be
safe for use again.
b) Sensitize the members of the community about the risks associated with radioactive
materials and how such materials should be handled.

Item 11

A senior two boy from a certain school was playing football with other boys, he is a very good
striker and while trying to score using the head, he jumped up but unfortunately on landing, the
right leg got a fracture. In trying to give him the first aid he felt a lot of pain and Headteacher
invited the parents of the boy to come and pick him from the school for hospital in order to trace
the broken bone. However, the Head teacher promised the parents that the school shall meet all
the medication charges and other related costs.

As a learner of physics help the parents to;

a) Differentiate and identify the medical device that the doctors shall use to trace the broken
bone.

b) Describe the mode of operation of the medical device identified in (a) above.

c) Applications of the device both in industrial and medical other than tracing the broken
bone.

Item 12

A home has a solar panel and a 12 V battery. The solar panel generates 52 V of d.c power but
only 14 V in needed to charge the battery. The home owner wants to install a bulb that
automatically comes

on when night falls. He is in possession of the following electronic components; an AND gate; an
OR gate, a NOT gate, a light dependent resistor L, which conducts when light falls on it, a 200 Ώ
 A concise approach to new curriculum physics questions by Buyinza David
resistor R and a 600Ώ resistor S. So far he has connected some of the components as shown in
figure1.

He is not sure if his system will function as required and he has failed to position the remaining
the components.

Task:

As a learner who has studied physics, help the home owner to:

a) Make necessary calculations to find out whether the charger circuit will be able to
efficiently charge the battery.

b) Identify the type of gate, X; giving reasons for your response.

c) Identify the gate to be connected at a, b and c so that the light bulb is automatically
switched on only when night falls.
d) Draw the circuit symbol for the gate chosen in (c) (i).
e) Draw the truth table for the gate chosen in (c)(i).

Item 13

During charity work in the hospital by Red Cross Society of one school, a certain liquid
containing a radioactive material spilled on one student accidentally, having been placed on an
open place by a medical intern. The hospital authorities immediately took the student for a
mandatory self-isolation within the hospital premises. The parents accused the hospital of
negligence and demanded to see their child in a weeks’ time.

Hint:
45
 A concise approach to new curriculum physics questions by Buyinza David
The liquid had an activity of 250 counts per second when tested immediately, with a half-life of 2
days.

The back ground count rate in the laboratory was 50 counts per second.

The student can be safe to re-join the public if the count rate falls below 10 counts per second.
Task:

Use your knowledge of physics to:

Determine how long the student will be self-isolated.

Enlighten the parents on the dangers of having their child at home without medical monitoring.
Explain to the medical intern how such materials should be handled.

Item 14

In a certain family, a child got an accident while playing with his friends and it was suspected to
be broken leg. The family was referred by nearby health facility to go for X-ray radiography.
The family already had some false information about how X-rays are produced and the related
dangers to their child, therefor they were unwilling to go for it. The X-ray machine requires a
voltage of about 4 kV to operate but the available main voltage supply is 10 kV.

Hint: Available resistors are 300 Ω and 200 Ω

Task

As physics learner,

Help the family to:

a) Clear the false information about the X-rays.

b) Understand how X-rays can be used to solve the problem of the family.

c) Using the knowledge of digital electronics, help your friends understand how a 10 kV
voltage would be used to operate the machine.

Item 15

A government has constructed an underground pipe to transport its oil over long distances. When
tested, the pipe is suspected to leak in a 100 m section and the leakage point is not easy to
identify since the pipe is underground. An engineer has proposed mixing some radioactive
substance of short half-life in the oil and using a detector to find the spot where the oil is leaking.
The radioactive substance to be used should diminish activity to less than 10 s-1 within 1 hour.
 A concise approach to new curriculum physics questions by Buyinza David
The engineer has identified one substance to be used and found out that its activity when mixed
with the oil, reduced from 480 s-1 to 60 s-1 in 30 minutes. The engineer has not yet drawn
conclusions about this choice of substance and may need your help.

Assist the engineer to:

a) Determine:

the half-life of the radioactive substance he is about to use.

the substance should now be mixed in the oil and start tracing the leakage.

b) Explain:

how the leakage is traced using this method

why the substance to be used should have a short half-life.

Item 16

At a major airport, X—ray machines are used to screen luggage and check for weapons and other prohibited
items. Recently, a suspicious item was detected in a passenger's bag, but the X—ray image was unclear,
causing confusion among security personnel. Further investigation revealed that the X—ray machine's
performance was affected by a nearby source of unknown radiation from a shipment containing isotopes of
uranium with a known half-life. The security team was concerned about the incidence but couldn't
understand how the machine operates, the type of radiation being produced by the radioactive substance, and
the likely impact on their health and environment. Hint:

• The nearby shipment contains isotopes of Uranium of half-life 4.5 billion years.

• The radioactive decay equation for Uranium atom is:

Task:

a) Using the knowledge of physics, help the airport security team understand;
b) The principle of X-ray imaging and why it is used for checking weapons at the airport.

47
 A concise approach to new curriculum physics questions by Buyinza David
c) Which radiation was being produced and what percentage of the radioactive substance will remain
after 22.5 billion years.
d) How to mitigate the impact of the radioactive material on the X-ray machine's operation and ensure
accurate luggage screening.

Item 17

A certain group of people from a village with a mining area are experiencing skin disorders and general
body weakness. Since they share a common water source, they decided to take a water sample to the
National Nuclear Research Centre. After two weeks, the nuclear centre sent the authorities a report with a
table as shown below.

Count rate (counts per minute) 1200 620 320 150 75

Time (minutes) 0 20 40 60 80

Task
Use your knowledge of physics to:

a) Help the local authorities estimate the time required for the water to remain until it is safe if the
background radiation in the area is 80 counts per second.
b) Identify the dangers associated with radioactive materials.
c) Suggest precautions to avoid potential problems associated with radioactive materials.

Item 18

It is established that a dairy company produces regular pasteurized milk that contains harmful bacteria.
To ensure the effectiveness of the pasteurization process and monitor bacterial growth, the company
adds a radioactive isotope tracer, Phosphorus-32 (P-32) to the milk.
The tracer helps in tracking and ensuring that the bacteria arc destroyed during pasteurization process.
However, P-32 is harmful for human consumption until its activity is reduced to a safe level. To
monitor the activity of P-32 in the milk to safe levels, the company uses a Geiger-Muller (GM) tube to
measure the activity over time. The results obtained from the GM tube measurements arc given in table
1.
 A concise approach to new curriculum physics questions by Buyinza David

Table l: GM tube measurements.

Count 22000 16000 11400 8200 5800 4000 3000 2400

rate(counts
min-1)

Time 0 2 4 6 8 10 12 14
(days)

Task:

As a physics student:

(a) Help the company by calculating the period to determine when the milk will be safe
for human consumption.
(b) Write an advisory note to educate the company on the dangers of exposing themselves
to radioactive substances and suggest any safety precautions that should be put into
consideration.
(c) Traces of radiations are still found in the milk even though there is no source. This is
attributed to background radiations. Explain the concept of background radiations and
suggest their common sources.
(d) The GM tube can efficiently detect cathode rays but fails to accurately detect X-rays.
Explain any three differences between Cathode rays and X rays.
Hint:
Phosphorus becomes inactive after its activity goes beyond 6000 counts per minute.

Item 19

49
 A concise approach to new curriculum physics questions by Buyinza David
A certain man came across the remaining bones of a person when was digging a pit latrine. The man took
one piece of the bones to his home and wanted to find out the time the bones had stayed in the soil. The man
consulted a scientist who told him that the age of a rotting plant or animal can be determined by a process
called carbon-dating. This is because animals and plants contain carbon-14 which is radioactive.

The scientist found out that the activity or counts per second pf the bone dug from pit to be 5. The
scientist then provided the man with a table of activity or counts per second and time in years
obtained when a fresh sample of human bone was used

Activity (counts 640 520 360 280 160 40

per minute

Time (years) 0 5 15 25 40 80

The man didn’t understand how to use the data to determine the age of the rotting bones which he found in
the pit

Task

As a student of physics,

a) Help the man understand the procedure to determine the age of the rotting bones he himself found in
the pit using the data above
b) Advise the man on the dangers associated with radioactive emissions and the precautions he should
take

Item 19

During charity work in the hospital by Red Cross Society of one school, a certain liquid
containing a radioactive material spilled on one student accidentally, having been placed on an
open place by a medical intern. The hospital authorities immediately took the student for a
mandatory self-isolation within the hospital premises. The parents accused the hospital of
negligence and demanded to see their child in a weeks’ time.

Hint:

The liquid had an activity of 250 counts per second when tested immediately, with a half-life of 2
days.

The back ground count rate in the laboratory was 50 counts per second.

The student can be safe to re-join the public if the count rate falls below 10 counts per second.
 A concise approach to new curriculum physics questions by Buyinza David
Task:

Use your knowledge of physics to: -

a) Determine how long the student will be self-isolated.

b) Enlighten the parents on the dangers of having their child at home without medical
monitoring.

c) Explain to the medical intern how such materials should be handled.

Item 20

An archaeologist discovered a mineral in the field. He got the sample of it which was monitored using a
GMT and the following data was obtained

Count rate 800 500 350 200 80 25

(counts per
minute)

Time(minutes) 0.0 1.0 1.8 3.0 5.0 7.5

He did not know if this material was radioactive until he got the above data. He had just handled the sample
with bare hands thinking it was safe.

Task

As a physics student;

1. Help the man know the half-life of the material

2. Help him know the possible health hazards associated with handling this material with bare hands
3. Identify safety measures to follow when handling this material

Item 21

A patient has been taken by relatives to a hospital, complaining of severe pain in the neck. A doctor has
admitted the patient in an isolated room and decided to examine the functioning of the thyroid gland. In the
process of the examination, a radioactive isotope has been injected into the patient to be used in the
diagnosis of the thyroid disorder. The activity of the radioactive isotope from the thyroid gland is detected
and recorded as shown in the table below

51
 A concise approach to new curriculum physics questions by Buyinza David

Activity 480 280 170 100 60 35

(counts per
minute)

Time (hours) 0 10 20 30 40 50

Whenever the relatives of the patient want to check on him in the isolated room, the doctor tells them to wait
for the right time (when the activity is equal to the background count rate of 40)

The doctor has also informed the relatives that if the right time for them to check on the patient comes, they
must observe precautions in the isolated room

The relatives have demanded to know the period they should wait before they can check on their patient but
no one answers them. They have also been left wondering what precautions are and why they should
observe them

You have heard the doctor talking to the relatives and they have contacted you to address their concerns.

Task

1. Use the data in the above table to determine how long relatives should wait before they are allowed
to check on their patient
2. Explain to the relatives why they should wait for that time before entering the isolated room
3. State the precautions they should follow when they enter the isolated room
4. Explain why the relatives should observe the precautions

Item 22

Students were told to research on the construction of a nuclear plant to provide a cheaper source of
electricity. They discovered that a radioactive element, uranium was used and it reacted as shown below
 A concise approach to new curriculum physics questions by Buyinza David
The students however couldn’t tell if one of the products was an isotope of an element with an atomic
number 36, which conditions are required for that reaction to take place, other benefits of radioactivity, and
how radioactive elements are handles

Use your knowledge of physics to;

a) To determine if krypton is an isotope of an element with atomic number of 36

b) Identify which conditions are necessary for the reaction to take place successfully
c) Identify other benefits of radioactivity
d) Precautions taken when handling radioactive materials

Item 23

The use of nuclear power is on increasing levels in many countries. Actually, many African countries are in
an attempt to adopted nuclear power usage on addition their existing sources of power.

However, governments are cautioned on the risks behind nuclear materials despite of the many advantages
compared to other sources.

As a student of physics.

a) Explain to the government of Uganda the advantages and disadvantages of nuclear power.
b) What measures should be put in place to manage properly the use of nuclear power.
c) Suggest some political dimensions of nuclear power.

Item 24

Places far from the referral hospitals have always had challenges with the diagnosis and treatment of certain
sicknesses. Now the government intends to provide X- ray machines to health centers in the in the country to
improve the diagnosis and treatment as a student of physics.

(i) Explain what X-rays are and what they can do in the community.
(ii) Explain how the machine will be effectively used.
(iii) Explain how X-rays are different from cathode rays.

Item 25

The article below was extracted from a newspaper by the ministry of energy and mineral development.

‘’nuclear energy is the energy in the nucleus or core of an atom. Atoms are tiny units that make up matter in
the universe. Nuclear energy can be used to create electricity but it must be released from an atom by a

53
 A concise approach to new curriculum physics questions by Buyinza David
process known as nuclear fission. A radioactive isotope of uranium 235
92 U which is the most widely used to

produce nuclear energy. If a uranium sample of mass 64kg decays to 4kg in 96days by emission of two alpha
particles and one beta particle to form thorium (Th), then large amounts of nuclear energy released can be
trapped and used to power mega manufacturing industries without directly affecting the environment. The
nuclear accidents in history that is the fukushima Daiichi accident of japan in 2011 and the Chernobyl
accident in Ukraine in 1986 greatly affected the environment negatively till date.

Nevertheless, the discovery of radioactivity has done a great role in enhancing the fields of medicine,
agriculture, industries and archeological sector. Thanks to the scientists Madame Marie curie, Pierre curie
and henri Becquerel’’

(Source; Wikipedia.org)

From the information above;

(a) What roles has radioactivity played in the medical and industrial sector?
(b) What dangers are associated with exposure to radioactive materials?
(c) Write down a well-balanced equation for the decay of uranium-235
(d) Determine the half- life of the uranium isotope

Item 26

Two students A and B started an argument about how the sun gives out heat and light. A, says some
materials inside the sun combine resulting into another, which makes heat and light to be produced. Student,
B says a material in the sun splints to form other small ones, then heat and light are produced. With no
agreement reached, they started fighting. Student A falls to the ground and cannot walk. On lookers rush
him to the hospital where they are told he has to go to a machine which uses electromagnetic waves to find
out if any of his bones is broken.

Student B, left scared goes to ease himself and he accidentally enters a room prohibited from unauthorised
hospital staff without noticing it and he is rushed away to a quarantine room for examination. One doctor
tells him that the room he entered had dangerous materials that release some things making them reduce in
weight but student B could not believe it. The doctor brings one which weighs 160g and after 140s it weighs
1.25g. the on lookers have no idea about the electromagnetic wave machine and worried of what it may do
to student A

TASK

As a learner, using your knowledge of physics, help student A, student B, and the on lookers on the
following
 A concise approach to new curriculum physics questions by Buyinza David
a) State and define the natural processes that caused the argument
b) Using a simple well labelled of the electromagnetic wave machine, describe how the waves used in
the machine are produce
c) Using calculations find the time it takes the mass of the material brought by the doctor to reduce to
20g
d) Mention the most likely dangers that student B may face
e) What advise would you give the people who would wish to work in the un-authorised room in the
future

Item 27

One of government’s manifesto is to improve on health care to the people by constructing and equipping
health facilities by installing an X-ray machine. In a report made by the news reporter of one of the papers
included;

Appreciation comments regarding the installed machine services

Complaint against statement out of bound that was put at the entrance where the machine was installed

A suggestion box was missing

Task

As a student of physics,

a) Identify scientific roles that account to appreciation attitude as a result of machine installation
b) With the aid of the machine setup, briefly describe its mode of work, to the public
c) Suggest the relevance of the statement out of bounds
d) Suggest the way forward as to enjoy the services of the installed machine

HEAT AND MECHANICS

Item 1

During holidays, a boy of mass 50 kg went to a play resort near the lake shores on a certain
beach and sat on one side of a see-saw at a distance of 2.4 m from its pivot. It was very hot that
day and the diurnal temperatures that were above 420C after afterwards he decided to enter the
lake and swim to cool himself. He was wearing heavy black shorts and white vest. After
swimming, he was left puzzled and wondering why his heavy black shorts dried quicker than the

55
 A concise approach to new curriculum physics questions by Buyinza David
white vest and beach cottages (semi-houses) roofed with grass instead of iron sheets were cooler
than those with iron sheets.

Hint: Specific heat capacity of the boy (human body) = 3.5 kJkg-1K-1

Task:

As a physics student;

a) Help the guide at the play resort to determine if another boy of mass 40 kg will restore
equilibrium in the see-saw if he sits at a distance of 3m from the pivot.

b) Assist the boy to understand what has made him puzzled and keep wondering.

c) Determine the quantity of heat lost by the boy if his temperature in the lake was
220C

Item 2

A pump is used to fill a tank by drawing water from underground well to be used at school
power house. In order to minimize on power consumption its use for limited time, the pump
works at a constant rate of 𝟐.𝟒 𝐱𝟏𝟎²𝐖 and it’s able to raise 0.188 m³ of water every minute
through a height of 6m. The cooks complain that it is slow at work. At the power house the cook
is always surprised because water pumped in the morning is always above the normal
temperature at 30℃ when measured using a thermometer which the cook checks before making
morning tea. The pump is said to be efficient if the ratio of its work out put to work input is
above 0.75 and the cook boils 9.5l of water for morning tea and 500g evaporated.

Support materials

Density of water is 1000kgm-3

Specific heat capacity of water = 4200Jkg-¹K-¹

Specific latent heat of vaporization of water 2.56×106Jkg−¹

Task.

a) Obtain the rate at which the pump works in raising the water and comment on its
efficiency.

b) Explain to the cooks why water pumped in the morning has such temperature.

c) How much heat is necessary to turn the lost volume of water into vapor.

Item 3
 A concise approach to new curriculum physics questions by Buyinza David
On a construction site a builder uses an electric lifter to transfer the mortar from the ground to a
height of 17.0m on the building. When power went off and work has to continue, the builders
got a rope, a pail of negligible mass with a handle that lift a maximum of 20kg of mortar. They
want to design a simple machine with a help of a grooved rim which can enable them resume
work.

Given that the rope has a maximum thermal strength of 3.8kJ.

Hint;

Assume all the potential energy is converted to heat energy

Task.

a) Help the builders to design the machine and guide the on how it works

b) Advise whether the rope will withstand the heat generated or it will break.

c) Suggest the necessary factor to consider that enable the rope to success fully execute the
work.

Item 4

A steel and tube industries company limited was contacted by the school to make a number of
new items to restock their kitchen. Among the items on the invoice are; saucepan, strainer,
saucepan covers (lids), ladles, cups and plates for students. The school did not specify the type of
materials these items should be made of and therefore, the procurement officer of the company
their raw materials supplier and the following was supplied following the invoice.

Plain sheets of copper

Plain sheets of aluminium

Melamine resin powder

Clay

Wood

For the production team to come up with the items requested by the school, they have to subject
these raw materials to either heat or force however these materials behave differently under these
two factors.

57
 A concise approach to new curriculum physics questions by Buyinza David
Support knowledge.

Heat capacity of copper is 400Jkg-1K-1

Heat capacity of aluminum is 900 Jkg-1K-

1 Task

As a physics learner, with reason(s)

a) help the production team to select the raw material suitable for each item to be
produced.

b) Explain at particle level how these materials behave when subjected to either heat or
when a force is applied.

Item 5

Workers at a construction site are meant to raise pieces of scrap of mass 6𝑘𝑔 through a height of
15𝑚. Their boss always complains that the workers do the work slowly, especially in the
afternoon when the temperatures are high and in the morning when it is cold. In response, the
workers claim their hands are burnt by the hot metals which slows them down. One of the
workers suggested they use a pulley of velocity ratio 4 and efficiency of 80%. The string they
used had a mass of 120𝑔 and a specific heat capacity of 2510𝐽𝑘𝑔−1𝐾−1, and the work done to
lift

the load would be converted to heat energy in the string at the contact point of the pulley and the
string would break if its temperature reaches 28℃.

Tasks

a) Explain why the metals are very cold in the morning and hot in the afternoon.

b) Draw a design of the required pulley and explain how it can be used to solve their
problem

c) Determine the minimum force required to ensure an efficiency of 80% is achieved.

d) Determine if the string suggested above will be suitable for the

purpose.
 A concise approach to new curriculum physics questions by Buyinza David
e) Suggest ways in which the efficiency of the pulley system can be
improved.

Item 6

During holidays, a boy of mass 50𝑘𝑔 went to a play resort near the lake shores on a certain
beach and sat on one side of the see-saw at a distance of 2.4𝑚 from its pivot. It was very hot that
day and the diurnal temperatures were above 42℃; afterwards he decided to enter the lake and
swim to cool himself. He was wearing heavy black shorts and a white vest. After swimming, he
was left puzzled and wondering why his heavy black shorts dried quicker than the white vest and
the beach cottages roofed with grass were cooler than those roofed with iron sheets.

Hint: specific heat capacity of human body is

𝟑.𝟓𝒌𝑱𝒌𝒈−𝟏𝑲−𝟏.

As a physics student;

a) Help the guide at the play resort to determine if another boy of mass 40𝑘𝑔 will restore
equilibrium in the see-saw if he sits at a distance 3𝑚 from the pivot.

b) Assist the boy to understand what has made him puzzled.

c) Determine the quantity of heat lost by the boy if his temperature in the lake
was 22℃

Item 7.

In certain town it’s a must for drivers to be tested together with their vehicles for road
worthiness. On certain day, a car started from rest and accelerated to 50m/s in ten seconds. The
driver maintained that velocity for 20s and suddenly decelerated to rest in 2s making him to crash
into the wind screen.

Task:

As a learner of physics,

a) Draw a graph to show the relationship between velocity and time for the car.

b) State whether the driver’s average velocity does not exceed the town’s speed limit
of 8m/s.

59
 A concise approach to new curriculum physics questions by Buyinza David
c) Find the rate at which the car’s velocity reduces

d) Explain why the driver crashed into the wind screen and how this can be prevented

Item 8

Zacharias is puzzled because his metallic doors are always very hard to close during day time
when it is shining too much, and he says that the same doors are very easy to close in the
evenings when the temperatures have lowered by considerable amounts.

Task:

As a Physics learner who understands better, the effect of temperature changes on matter:

a) Explain the cause and applications of Zacharias' puzzle in our daily life

b) Basing on the kinetic theory, explain why liquids expand much more than solids for the
same temperature change?

c) Explain the Biological importance of the anomalous expansion of water in preserving

aquatic life in countries like Switzerland where temperatures go below 00C

Item 9

Some bottles of colorless liquids were being labelled when the technicians accidentally mixed
them up and lost track of their contents. 𝟏𝟓. 𝟎 𝒎𝒍 sample withdrawn from one bottle weighed
22.3 g. The technicians knew that the liquid was either acetone, benzene, chloroform, or carbon
tetrachloride. He however has challenges identifying the right chemical to label.

Hint 1ml=1𝒄𝒎𝟑

LIQUID Acetone Benzene Chloroform Water Carbon

tetrachl

Oride

DENSITY 0.792 0.899 1.487 1.000 1.595

a) What was the identity of the liquid? (Clearly show each step of your work out) .
 A concise approach to new curriculum physics questions by Buyinza David
b) Using the table above Name those liquids which can float on water and explain why they
float on water.

c) Using the table Name those liquids on which water floats on top and explain why water
floats on those liquids named.

Item 10

In your trading Centre, empty mineral water bottles are scattered everywhere, thus causing
blockage of trenches. A business man came to your trading Centre to buy empty mineral water
bottles and pays according to the mass of each bottle. The businessman only buys bottles whose
mass exceeds 30g. Your brother wants to sell his mineral water bottle but wants to know its mass
before selling to the businessman and has no access to any instrument measuring mass.

Task:

You are given a meter rule, a knife edge, a 100g mass and two pieces of thread. As a student of
physics describe how you will assist your brother to determine the mass of the bottle so that he is
able to sell it. In your investigation you find that when a mass of 100g is placed 15.0cm from the
knife edge placed at the Centre of gravity of the meter rule, the bottle should be placed 37.5cm
for the meter rule to balance. Assist your brother to find out whether the bottle can be sold to the
businessman.

Item 11

A certain home owner intends to put up a metallic tank of height 4 m with a maximum volume of

5000 l fitted with an electrical heater which supplies 20,000 kJ of heat energy as shown in figure

1.

61
 A concise approach to new curriculum physics questions by Buyinza David
The home owner found out that the heater was fitted at the lower part of the tank but he did not
understand why it was done like that. Just before the hole for the outlet pipe was drilled at point
A, the home owner told the person with the drill that the correct position was either B or C.

Task:

As a learner of Physics;

Explain to the home owner why;

a) the electrical heater was fitted at the lower part of the tank and how eventually all the
water gets hot.

b) the outlet pipe was drilled at point A.

c) If the initial temperature of the water in the tank is 20 o C, help the home owner to find
out if the heater is working.

d) Advise the home owner on measures that can be taken to ensure that the tank stand can
withstand the weight of the tank and water for a long time.

(Use: Density of water = 1000 kgm-3. Specific heat capacity of water = 4200 J kg-1 K-1.
Acceleration due to gravity = 10 ms-2)

Item 12

A certain hotel has its bathrooms situated on the 3rd floor of a building. A customer of the hotel
expects to bathe water at 32 o C. The hotel provides 10 litres of water at 20 o C to each customer.
A boiler on ground floor heats water to 80 o C for the customers to use. The hotel management
does not allow its workers to carry the hot water via the staircase.

Task:

Having studied physics;

a) help the hotel management to determine the quantity of hot water to be given to a
customer for bathing.

b) advise the hotel management on how to keep the boiled water hot for a long period of
time without keeping the boiler on.

c) explain to the management how the water from the boiler can reach the third floor safely.

(Use: Density of water = 1000 kgm-3. Specific heat capacity of water = 4200 J kg-1 K-1.
Acceleration due to gravity = 10 ms-2 )
 A concise approach to new curriculum physics questions by Buyinza David
Item 13

A jackfruit of mass 2500g is plucked off fruit the jackfruit tree from a height 4m above the
ground and falls freely. The jackfruit accelerated to the ground and hit the ground.

Task.

As a learner of physics;

State and calculate the form of mechanical energy stored in the jackfruit before falling.

 Determine the kinetic energy of the fruit as it hits the ground stating clearly the
assumption and hence calculate the velocity with which it hits the ground.

 Explain why the jackfruit comes to rest after hitting the ground and does not bounce
back to the original height hence state the law shown by the behavior of the fruit.

 Determine the kinetic energy possessed by the fruit as it passes a point 1.5m above the
ground.

Item 14

For man to earn a living, he has to do some work. A certain business man has to climb 20
stairs each of height 20cm to reach out his business store on the first floor of their business
Arcade in Kampala city.

Task:

As a physics scholar;

a) Help a lay man to understand the meaning of the term “work” and state its appropriate S.I units.

b) If the businessman has a mass of 73.5kg and is holding a bag of mass 1.5kg, determine
the work done by the man when climbing the stairs and the power dissipated in 5minutes.

c) Explain why it is easier for the man to move down stairs than climbing
them.

Item 15

At a certain construction site in given town casual labourers were required to raise construction
materials to the 3rd level which was 2400m from the ground, they requested for a crane
consisting of a pulley system of velocity ratio 7. The operator raised a total load of 40,000N
using an effort of 8,000N.

63
 A concise approach to new curriculum physics questions by Buyinza David
Task:

As a learner of physics;

a) Draw a diagram to illustrate the pulley system contained in the

crane.

b) Determine the efficiency of the pulley system.

c) Explain why the efficiency of the machines is always less than 100% and state how it can
be improved.

d) State the applications of pulleys in our daily

life.

Item 16

A heap of weed of mass 3 tones is moving towards the turbines at the Jinja power station. A
group of engineers needs to use a machine operating at 20 kW for five minutes, to remove the
weed from the river and place it at the bank, which is 15 m above the river

a) Determine the efficiency of the machine and explain its value.

b) Explain how the machine is capable of floating in the water yet it is denser than
water.

Item 17

The figure below shows a uniform metallic rod of length 4.0m pivoted at its centre that is used
at a certain children’s play resort.

Task:

As a physics scholar;

Given that a boy of mass 48kg sits 1.5m from end A. Help the guide at play resort to determine
if another boy of mass 40kg will restore equilibrium in the beam if he sits at a distance of 0.6m
from the centre.
 A concise approach to new curriculum physics questions by Buyinza David
Identify two other instances in which the knowledge in this scenario would be applicable in real
life.

With the boys off the rod, explain what would happen to the beam if the end B was heated by a
considered hot flame.

Item 18

Mr. Onyango and Mr. Oketcho had an argument over the width of the path that separates their
land. Mr. Onyango claimed that the path is 12 feet wide. However, Mr. Oketcho claimed it was
10 feet. When the chairman intervened, he measured the path with a foot rule and found out that
it was 8 feet, after that the three were in disagreement.

Tasks

a) Why did Mr. Onyango and Mr. Oketcho fail to agree on the width of
their path?

b) Why do you think the chairman got a different measurement?

c) As a physics learner, how would you solve the

disagreement?

Item 19

On a hot day, a student dropped three ice cubes at -6℃ in a jug of water at room temperature. If
the final temperature of the mixture after all the ice has melted was 16℃

Tasks

a ) Sketch a temperature-time graph for the ice.

b) Describe the key features of your graph in (i) above.

Item 20

Your elder sister has just received his S.6 results and she scored AAA in her combination PCM.
He is soon going to apply for a course on Bachelors’ degree level at Uganda’s greatest
University, Makerere. However, your sister is not sure of which career path he should apply for.
He needs someone to guide her through the right career opportunity she can peruse in future.

Tasks

65
 A concise approach to new curriculum physics questions by Buyinza David
a) Write down how you can help your sister in identifying all possible suitable physics
careers she can Pursue at the Makerere University.

b) Identify the likely challenges and benefits in some of the careers

available

Item 21

You are to drive 300 km to an interview The interview is at 11:15 A.M. You plan to drive at 100
km/h, so you leave at 8:00 A.M. to allow some extra time. You drive at that speed for the first
100 km, but then construction work forces you to slow to 40 km/h for 40 km.

a) What would be the least speed needed for the rest of the trip to
arrive in. time for the interview?

b) And knowing how dangerous over rushing to beat the deadline can be to your life and
other road users, explain how best you can overcome these dangers as you drive on your
way to the interview?

Item 22

When a 𝑉𝐻𝑇 (𝑉𝑖𝑙𝑙𝑎𝑔𝑒 𝐻𝑒𝑎𝑙𝑡ℎ 𝑇𝑒𝑎𝑚) member visited a patient in Kamwokya

Hospital, he had to determine the temperature of the patient before giving the medication.

Tasks

As a medical doctor, help the VHT member to identify the points of reference that can help him
to calibrate the instrument he has to use to determine the patient’s body temperature.

The VHT member used mercury in glass thermometer.

As a physicist, identify the physical property used by this thermometer. Why do you think the
VHT member chose mercury instead of Alcohol as a thermometric liquid? (Give one reason)

Item 23

In your community, there is a village man moving around selling four different objects claiming
they are made of Gold. Each object has a known mass. The objects are a tin cylinder, a
container cube, a steel spanner and a slicing board. Mugisha wants to buy items for home use
but he is not sure where what is buying is purely gold. Help Mugisha make a better choice.

Item 24
 A concise approach to new curriculum physics questions by Buyinza David
There is a parent project in your school to construct two rectangular pit latrines. one at the girls
‘wing and another at the staff quarter’s wing. However, the Board of Governors and the school
administration have failed to agree on the choice of materials to use in construction

Tasks

using the knowledge and skills learnt in ‘’mechanical properties of materials’’ Suggest the choice
of materials you would advise the school board to use in the construction of the latrines.

Item 25

A maize flour producer located in a certain trading centre in Eastern part of Uganda has heavily
loaded his lorry truck with bags of quality maize flour. Before starting the journey that is
estimated to be 1800Km and takes 3days to transport and supply maize flour to PEAS schools in
the echoes cluster, the producer first checked his truck tyre pressure and temperature which was
600kPa and 15°𝐶 respectively in the morning. The producer started the journey early morning
and had a stopover along a tarmac road on a hot sunny day and turned off the engine of the truck
for some time. As the day progressed temperature in the tyre increased by three times the initial
temperature and the nearby community had a blast of a bomb and they were all scared after a
short time of parking by the producer.

Task

As a Physics student;

a) Help the producer to determine his average speed for the journey in 𝑚𝑠−1.

b) Support the producer to know the final temperature in kelvins and pressure of the
tyre.

c) Explain to the producer why the truck tyre had to burst.

What safety precautions should the producer have taken regarding tyre pressure and
temperature before embarking on the long journey especially on a hot day?

Item 26

Jacob a student in a certain school in Fort Portal tourism city is a class counsellor who is
responsible for picking books from the library to classroom. The library is a temporary structure
made up of tents painted black. Jacob normally runs to reach the library because of the big

67
 A concise approach to new curriculum physics questions by Buyinza David
distance from the classroom, one day he ran from class via main hall up to a velocity of 5m/s in
10s to reach where the library is. However, after picking books, he got tired and rested in the
library for 20 seconds.

While in the library he felt uncomfortable and returned back to class and reached in 10s. The
following lesson he ran from class via science laboratory and reached the library with a
velocity of 5m/s in 5s. He picked books and also rested for 20s then he came back to class in
5s. 4

Task

As a student of physics,

a) Advise Jacob the shortest route he should take so as to minimize

wastage of time and explain why?

b) Explain to class members what could be possible reasons why the counsellor felt
uncomfortable while in the library

c) Advise the school the kind of structure they should put up for the school library and
explain why?

Item 29

Faisal constructed the latrine for his tenants but People from the neighbourhood are complaining
about the bad smell from the latrine.

Tasks

a) Why do you think people who are not inside or near the latrine are getting the smell?

b) People also reported that on cold days the situation is worse than on hot days. They are
wondering why this is so. Give a reason why this is like that.

Which advice do you give to Mr. Faisal?

c) Give two applications of the above mechanism that makes the smell of the latrine to be
in the neighbourhood in rest life?

d) It’s known that a stone can move more freely in air than in liquid. Using your
knowledge of states of matter, explain why that happens.

Item 30
 A concise approach to new curriculum physics questions by Buyinza David
A rider who has been using a simple bicycle has purchased a new and improved one. The total
mass of the rider and this new improved bicycle is 80 kg. The rider uses this bicycle to go up
a hill of height 5 m in 20 seconds and he is 75% efficient. On the other hand, the simple
bicycle has two toothed wheels are connected by a chain, with 48 teeth in the big toothed
wheel and 16 teeth in the smaller toothed wheel. The rider is looking for more explanations to
convince his brother that he is not just wasting money by buying the improved bicycle

Using your Physics knowledge,

help the brother to:

a) determine the velocity ratio of the simple bicycle.

b) explain the advantages and disadvantages of having a high velocity ratio in the
connected toothed wheels.

c) determine the power used by rider to move up the hill using the improved
bicycle. understand why the rider preferred to use the improved bicycle
for riding up a hill. Explain why it is important for the rider to sweat.

Item 31

A S.4 child and her mum have gone to buy some cooking utensils. The mum explains to the shop
attendant that she usually gets problems in cooking beans since they take long to get ready when
being boiled in water, leading to wastage of energy and time. The attendant shows her an
appliance claiming it cooks fast due to its features. The lady is not convinced about the appliance
and wishes to get more information before buying it; so, she asks the child to explain more.

Task:

Assuming that the lady is your parent or guardian, use knowledge of Physics to educate her on:

a ) why the appliance makes the beans get ready

the steel pan should have a plastic handle.

b) the steel pan should have a thick body.

c) why steel is an important property in this appliance.

d) why the bottom of the pan and its sides are made of different colours respectively.
69
 A concise approach to new curriculum physics questions by Buyinza David
e) the different means by which heat from the heat source can reach the beans.

Item 32

A business woman intends to install a storage gravity water tank in his home which should
supply pressure at 10 kPa. She also needs her tank to have a ladder with steps each of height 40
cm for climbing up to clean his tank. Due to extreme weather conditions the tank may burst as a
result of the expansion and contraction of the pipes used. To avoid this, the business woman has
been advised to buy a pipe made of a suitable material and get a person who will fit them well.
Unfortunately, she does not have enough knowledge about such installation works and is looking
for further assistance.

Hint:

Density of water = 1gcm-3

Acceleration due to gravity = 10ms-2

Task

Using the knowledge of physics to help the business woman to;

determine:

1. the height the tank must be raised to.

2. the number of steps to be put in the ladder.

3. understand:

4. how the pipes would be connected to the tank.

5. how the suitable material of the pipes to be used would be determined.

Item 33

Your friend travelled in an old ramshackle vehicle for an appointment. The first 60 km they
covered were on a rough road and the journey turned out to be bumpy and she felt like she was
being carried in a wheel barrow. This made her recall Hooke’s law which they learnt in Physics
at school. After the bumpy section, the road was now smooth for the remaining 20 km where
they

moved at a speed of 80 kmhr-1 which is the traffic speed limit for that road. For the entire journey
she spent 1 hour on the road and unfortunately missed the appointment. She has been given a
 A concise approach to new curriculum physics questions by Buyinza David
new appointment at the same time tomorrow. As she narrates this story to you, she is not sure if
she will be able to make it for the appointment, and is seeking for you advice and help in this
matter.

Task:

Help your friend to:

a) differentiate between a wheelbarrow and the car, with reference to her experience.

b) Describe the important property of materials that is useful and applied in the vehicle for a better
experience.

c) State the law that applies to materials as referred to in your friend’s experience.

d) determine the speed at which she moved on the bumpy section of the road.

e) determine and advise her on how much earlier she should start the journey if she is to be
on time for the new appointment, given that she is to use the same vehicle on the same
road.

Item 34

A business lady operates a restaurant which serves food and drinks. In the morning as she was
driving her car to his restaurant, it developed a problem. There was a lot of steam coming from
the bonnet and the engine stopped working. The mechanic she invited told her that the engine
had overheated because there was little water in the radiator. After filling the radiator with water,
the car started working. When she reached her restaurant, she prepared 0.02 kg ice cubes for
customers who wish to add them to their drinks. She then steamed the matooke for lunch and
proceeded to make her special drink that she serves out in plastic glasses that hold 0.5 kg of the
drink.

Task:

Assist the business lady to;

a) understand the features that make her car radiator efficient for its purpose.

b) identify the various states of water that she used that day.

c ) explain why each of the states of water works very well for the purpose it served that day.

71
 A concise approach to new curriculum physics questions by Buyinza David
d) determine the specific heat capacity of the special drink, given that a customer needed
four ice cubes to reduce the temperature from 300C to 100C.

Hint: Specific latent heat of fusion of ice is 336000 Jkg-1

Specific heat capacity of water is 4200 Jkg-1K-1

Item 35

A class intends to undertake a physics project of making a thermometer to be used in a physics

laboratory. At the planning stage, the following questions have come up;

How to select the suitable liquid to be used.

How to come up with the graduation on the thermometer.

They have approached you for some ideas to help them produce a working product.
Task:

As a physics learner help your friends to,

understand;

a) What they should consider when choosing a suitable liquid for this project.
b) How their thermometer should be graduated.
c) determine the density of the liquid to be used in the absence of a measuring cylinder or
any other apparatus for measuring volume.

Hint:

the volume of the liquid required is 5cm3.

knowledge of principles of moments to determine density.

Item 36

Your parents operate a diary business and buy five jerry cans daily. Before buying milk from any
farmer, its purity is tested using a hydrometer. One evening the hydrometer accidentally fell
down and stopped working yet the milk had to be tested. You advised them to keep the milk into
a refrigerator which automatically switches off when the temperature of the milk has dropped
from room temperature to a temperature of 10 0C. The parents were worried that their milk
would get spoilt and hence make losses; they wanted you to explain and assure them if your
advice would really work.
 A concise approach to new curriculum physics questions by Buyinza David
Hint;

Volume of each jerry can of milk is 20

litres

Room temperature = 240C

Specific heat capacity of milk = 3.14 Jkg-1K=1

Density of pure milk = 1035 kgm-3

Materials to use include; beam balance, measuring cylinder and beaker.

Task

Using the knowledge of physics, assist your parents to;

determine the purity of the milk in absence of a
hydrometer.

a) understand how much heat energy is withdrawn by the refrigerator from the milk.

b) understand how the features of the device you proposed, are able to save the milk from
getting spoilt.

Item 37

In a certain home, it is the children’s responsibility to draw water for cooking and also to boil
it for

drinking. They draw the water from an underground well using a rope and a bucket. The children

have raised a complaint to their father that pulling water using a rope and a bucket is tiresome
and are

suggesting that a simple machine for drawing water be designed for them. Every day, they use an
aluminium saucepan of mass 2 kg to boil 10 litres of water from a temperature of 240C to 900 C.
The father is planning to address his children’s concern but is not certain of how to solve it, and
is looking for guidance.

Task:

Using the knowledge of physics, help the father to;

a) design the simple machine that can be used and explain how it works.

b) understand how to improve on efficiency of the machine designed in (a)(i).

73
 A concise approach to new curriculum physics questions by Buyinza David
understand how much heat energy is used daily by the family to boil drinking water.

Use;

Specific heat capacity of aluminium = 900𝐽𝑘𝑔-1 𝐾-1

Specific heat capacity of water = 4200𝐽𝑘𝑔-1 𝐾-1

Density of water = 1000𝑘𝑔m-3

Item 38

A friend of yours wants to buy a hybrid car. He was conducting a driving test
to evaluate the efficiency of the car. During the test run, the 1500kg car
accelerates uniformly from rest to a speed of 40ms−1 The car is considered
efficient if the average power output exceeds 200kW over a distance of 100m
on a straight track. All heat generated by the car's engine during acceleration
(work done) is absorbed by the coolant.

Task

As a student of Physics, help your friend

to;

a) Find out whether the engine of the hybrid car is working efficiently
and advise him whether to buy it or not.

b) Explain how heat is transferred from the engine to the coolant

during the acceleration.

c) If the initial temperature of the coolant was 250C. At what

temperature was the engine operating during the acceleration before
absorption by the coolant.

Use

Specific heat capacity of water=4200Jkg-

1
K-1

Item 39
 A concise approach to new curriculum physics questions by Buyinza David
Due to traffic-c jam in a certain town, the traffic section has
set 60ms-1 to be speed limit in order to reduce accidents. On
a certain day, truck A, of mass 1.2×103 kg collided with

another truck B, of mass 2000kg which was moving at a

speed of 50 ms-1 in opposite directions. The trucks got stuck
together after collision and moved at a speed of 0.15ms-1
before coming to a complete stop with a deceleration of 2ms-
2

Kinetic energy of the trucks was converted into heat energy.

Support:

The heat capacity of the material of the trucks is

1.28×106JK-1

Task:

As a physics student, help the traffic section to determine;

1. Whether the cause of the accident was over speeding of truck A

2. the distance moved after collision before coming to complete stop.

3. the temperature difference of the trucks.

Item 40

Workers at a construction site are meant to raise pieces of scrap of mass 6kg through a height of 15m.Their

boss always complains that the workers who carry the pieces of metal do the work slowly,
especially in the

after noon when the temperatures are high and in the morning when it is cold. In response, the workers claim

their hands are burnt by the hot metals which slows them down. One of the workers suggested
they use a pulley of velocity ratio 4and an efficiency of 80%.

Use your knowledge of physics to;

1. Explain why the metals are very cold in the morning and hot in the afternoon.

75
 A concise approach to new curriculum physics questions by Buyinza David
2. Draw a design of the required pulley and explain how it can be used to solve
their problem. Determine the minimum force required to ensure an efficiency
of 80% is achieved
The string they used had a mass of 120g and a specific heat capacity of 2510 JKg-1 K -
1
and the work done to lift the load would be converted to heat energy in the string at
the contact point of the pulley.

Hint; The string would break if its temperature reaches by 28 0 C.

1. Determine if the string suggested above would be suitable for the purpose.

2. Suggest ways in which the efficiency of the pulley system can be improved.

Item 41

During a party, 2 litres of water at 24 0 C were served to a man and a woman. They complained
that it was warm and were given 50g of ice at -10 0 C blocks. They mixed the water and blocks in
a wooden container with a negligible specific heat capacity. They were surprised by the ice cubes
disappearing in the water. The man put his mixture in a plastic container (shc = 2800 JKg-1 K-1)
while the woman put her mixture in a metallic container (shc = 800 JKg -1K-1)

They were surprised to find their water at different temperatures after

some time.

Specific Heat capacity of water = 4200 JKg-

1
K-1

Latent heat of fusion of ice=340000 JKg-1

Use your knowledge of Physics to;

1. Determine if the water cooled when mixed

with ice.

2. Why do the ice cubes disappear when mixed

with water?

3. Explain why there was a difference in temperatures in the water kept in the plastic and the
metallic container.

Item 42
 A concise approach to new curriculum physics questions by Buyinza David
A certain high way restaurant in one of the towns in Uganda is known to provide warm water
to its customers for washing hands.

An attendant who works in this hotel was given two similar plastic cylindrical tanks each with
a cross-sectional area of 18380cm and height of 5.5m. One of the tanks is painted white and the
other painted black. Attendant is supposed to store 10m3 of warm water in any of the tanks. She
is worried on which tank she can use to keep water and accommodate all the available water.

To ensure smartness in the restaurant, each tank is supposed to be supported on

plastic stands as shown in the figure,

Task

As a learner of physics,

Help to explain to the attendant on;

1. If one of the tanks was to be used for hand washing and the
owner of restaurant wants to put a tap on it,

2. The tank she would use to store the required amount of

water.

3. The type of tank that would keep water for customers at

required temperature.

4. Show him by letter K, the position where the tap can be put.

5. Explain to the restaurant owner on the choice of position K

77
 A concise approach to new curriculum physics questions by Buyinza David
6. What advice would you give to the restaurant owner on the
measures he would ensure for the tank stand to withstand weight
of the tank for a long time

Item 43

While driving passengers, a taxi driver got frightened when a flying bird hit the
wind screen. He then suddenly applied breaks and stopped that led the car tyres to
burst and the passengers were seen to jerk forward and backward.

As soon as the driver went out of the vehicle to check what had happened, he
touched on the cover of the engine part of the car (bonnet) and it was so hot. On

opening the bonnet, it was not in contact with the engine yet the engine was
also hot.

The figure shows the motion of the vehicle before all this happened.

The taxi driver did not know the exact location he was, so that he could direct the
mechanic to bring him new tyres to replace the burst tyres.

1. Help to tell why passengers had to jack forward and backward

when the driver suddenly braked.
2. Help the driver to explain why the bonnet was so hot when he touched it.
3. Advise the taxi driver to direct the mechanic the exact location he would find him so he could deliver
the new tyres

Item 44
 A concise approach to new curriculum physics questions by Buyinza David
Your sister leaves home for work at 7:20am and as a must carries tea in a flask. One morning she needed to
prepare the tea she carries but she remembered that the only water she had in the house was 5 litres in a
saucepan of 0.2kg in a deep freezer.

On removing the saucepan from the deep freezer, she realized that all the water had turned into a block of
ice. It was 7:00am and she was worried about leaving home late, but decided to heat the saucepan containing
the block of ice with her heater rated 4.22kW, until all the ice turned into water boiled ready for tea

Hint

Specific heat capacity of the saucepan=900Jkg-1K-1

Specific heat capacity of water is 4200Jkg-1K-1

Specific latent heat of fusion of ice is 33600Jkg-1

Density of water is 1000kgm-3

Boiling point of water is 1000C

Temperature of ice in the sauce pan is 00C

TASK

1. Determine how long it took your sister to boil the water

2. Explain whether or not your sister was able to leave home for work at 7:20am

ITEM 45

A driver parked the car under a hot day sunshine to have lunch at home and noticed that he was late to pick
up his boss from a meeting in town. Worried as he was about being late, he drove as fast as possible for 120
minutes but as he approached the town, one of the car’s tyre bursts, prompting him to take the car to a
garage. He noticed when the mechanic opened the car radiator that it was painted black and water was being
used as a coolant but couldn’t understand anything. He also questioned what caused the tyrre to burst but
couldn’t get satisfactory explanation having been answered that he was over speeding

Hint

The car travelled 300km before the tyre burst

The speed limit of the road is 80km/h

Task

79
 A concise approach to new curriculum physics questions by Buyinza David
1. As a physics student, help the driver,
2. Understand why water is used in the car radiator
3. Explain what caused the tyre to burst
4. Know if he was over speeding

Item 46

A man set off for a destination 250km away from his home at 4:00am to be at his workplace at 8: 00am. The
speed limit on that road is 80km/h. he set off on the journey without fastening his seatbelt and drove at an
average speed of 60km/h for the first 2 hours.

He saw a truck that had fallen covering the whole road and stepped on his brakes which brought the car to a
sudden stop. This made him jerk forward almost crushing into his windscreen.

The man stopped for 45 minutes and resumed his journey, reaching his workplace on time. He got out of his
car and discovered it was very cold so he decided to wear a black sweater which was against the choice of
his workmates who said he looked smart in his white shirt

Use your knowledge of physics to;

1. Determine if the driver exceeded the recommended speed limit

2. Explain what made the man jerk forward
3. Explain to the man’s workmates why he chose a black sweater

ITEM 47

A plumber was designing a water pump system to transport water from a higher reservoir to a lower
reservoir and vice versa. However, he encountered challenges due to the anomalous behaviour of water at
certain temperatures. The plumber realized that the pump will need to lift 1000 litres of water from a depth
of 3000cm to a height of 10000cm at 270C and discovered that the efficiency of the pump decreases at
temperatures close to 40C. he notified the community members about this situation which may affect the
process of water supply they count understand

Hint

The densities of water at 40C and 270C are 1000kgm-3and 998.2kgm-3 respectively

As a learner of physics, help the community members;

a) Understand the behaviour of water encountered during the design of the water supply system
 A concise approach to new curriculum physics questions by Buyinza David
b) Explain the mechanism of supplying water from the higher reservoir to a lower reservoir and from a
lower reservoir to a higher Reservoir
c) Know the additional energy required to supply the water from 300cm to 1000cm at 40C compared to
temperature of 270C

ITEM 48
Your father has hired a tax to take the whole family to the village but he is not sure of the total distance from
home to the village. The taxi driver has informed your father that he charges shs 2500 per km moved and
your father should not worry about the distance since he installed a machine in his taxi that shows the
motion of the taxi inform of a velocity time graph. The taxi has set off from your home to the village and the
velocity time graph for the journey is shown below

On reaching the village, the taxi driver has requested for his payment. However, your father has refused to
pay until he is helped to understand how the graph drawn by the machine is related to the distance travelled

Task

Help your father

a) Understand the motion of the taxi from home to the village

b) Determine the amount of money he has to pay to the taxi driver

ITEM 49

Your family hires three vehicles for a convoy to attend a wedding ceremony of one of your relatives.

The hiring company charges a fee according to the distance moved. On a hot day, the team sets off from
home with inflated balloons at 7:00am and attains a maximum velocity of 72km/hr. in 60 minutes.

On reaching the highway road, it maintains this velocity for 90 minutes, finally it reaches the reception at
10:00am.

81
 A concise approach to new curriculum physics questions by Buyinza David
It was observed that some balloons burst and only a few were left. Later in the evening it rained heavily and
cars failed to reach back home due to slippery roads.

Task:

As a physics student;

(a) Help your family members compute the distance from home to church.

(b) Explain to your relatives the reason(s) why most of the inflated balloons burst.

(c) Provide guidance to the car owners to avoid the problem faced during the return journey.

ITEM 50

An ambulance is transporting critical medicine from the city Centre to an upcountry district. The
medicine must be kept refrigerated, and the mini refrigerator in the ambulance is chargeable.
However, the ambulance runs out of fuel, and the driver stops a passing pickup truck for help. The
pickup truck driver offers to give some fuel, but when checking the battery, the ambulance driver
realizes it is draining quickly. The refrigerator indicates it has only 3 hours of operational time left.
The remaining distance to the destination is 150km.

The only method they can use to get fuel from the pickup is through a pipe.

The amount of thermal energy required to maintain the refrigerator's internal temperature should be higher
that than 450000J

Task: As a learner of physics, you have been requested to;

a) Explain using diagram how the driver can get fuel using a pipe from the pickup truck to his tank.
b) Advise the driver on the minimum average speed the driver needs to maintain to ensure the
medicine remains properly refrigerated upon arrival.
c) Establish whether there is enough energy to maintain the refrigerator's internal temperature if the
refrigerator's power rating is 50 W.

Item 51

Two cars collided at a junction: one car was traveling northward and the other southward. The driver
of the southbound car claims that the northbound driver was over speeding. The traffic police are not
sure of who is at fault. A witness stated that the cars travelled together after the collision. One of the
drivers was not wearing a seatbelt. To identify a vehicle which was over speeding or braking heavily
 A concise approach to new curriculum physics questions by Buyinza David
before the crash, the risen tyre temperatures can provide physical evidence. The police used an
uncalibrated thermometer to measure the temperature of the tyres as follows:
Length of the mercury thread when in contact with the tyre: 40cm
Length of the mercury thread at the ice point: I0 cm Length of the
mercury thread at the steam point: 80cm Additional Information:

Mass of the car travelling northward: 2000kg

Mass of the car travelling southwards: 1800kg
Velocity of the car travelling southwards before the collision: 70km/hr.

Common velocity of the two cars after the collision: 35km/hr.

Speed limit on this road: 70km/hr.

Task: As a learner of physics,

a) guide the police on whether the pickup was over speeding.

b) Advise the driver who was not putting on the seat belt on how it can safeguard his live
c) Assist the police to get the correct tyre temperature.

Item 52

An investor seeking to establish a ceramics company requires guidance on using a hydraulic press to
manufacture concrete pavers, blocks and bricks. The hydraulic press supplier contacted. provided a
manual booklet with a sketch drawing to help the investor understand the technical aspects. The manual
has instructions for the hydraulic press to be operated effectively. One of the instructions given, is that the
temperature of the hydraulic fluid in it should not rise beyond 20 0C. This is crucial to ensure the press's
efficiency and longevity. The investor who is not a physicist seeks guidance to venture into this business.

Task:

AS a physics student;

a) Explain to the investor the working principle of a hydraulic press.

b) Explain why oil is used instead of air in the hydraulic press.
c) If 340000 J of heat in the fluid is generated by the hydraulic press during operations. Determine
whether it will remain effective if the entire system contains 10 litres of the fluid.
d) If the hydraulic press has an efficiency of 80% and needs to press concrete requiring an output
work or 2000 J. Advise whether it will be in position to start operating.

83
 A concise approach to new curriculum physics questions by Buyinza David
e) Explain the main components of concrete and why it is preferred as an effective constructional
material.

Hint

Specific heat capacity of the hydraulic fluid is 1750 Jkg-1 K-1

The minimum energy input for the press to start working is 1600 J

I litre is equivalent to 0.001 m3

Density of hydraulic fluid = 800 kgm-3

Item 53

After driving for 8 minutes on a slippery road at a constant speed in a busy town, the driver of a fully
loaded passenger bus notices a boda-boda rider suddenly crossing the road to pick up a customer. The

driver immediately applies the brakes and decelerates but still slightly hits the rider causing damages to
both the bus and motorcycle. It takes the bus 80 seconds from the moment the brakes arc applied to come

to a complete stop. during this time, it is noted that most passengers hit their heads on the scats Infront of
them. However, during the incident of the accident several boda-boda riders convene and threatened to
beat the bus driver for damaging their colleague's motorcycle. However, officers from the police and the
bus's insurance company were called upon to come to the scene to access the situation and also calm down
the rowdy riders. Upon assessment. the following points were noted:

Passengers were not wearing scat bells

Bus tyres were worn out
A significant amount of' heat had been generated due to braking.
the police officers inquired if the driver had not sighted the road marking signs shown in figure 3

Figure 3: Road marking signs.

 A concise approach to new curriculum physics questions by Buyinza David

Task:

As a physics student respond to the following;

The bus had travelled a total distance of 5.3 km from when it started the constant speed to when it
uniformly decelerated to rest

a) determine whether the insurance company will be in position to compensate for the damages.
b) Suggest reasons why the loaded bus took long to come to rest.
c) The police were also interested in investigating whether the brakes were in good condition. If
the bus was using steel brakes of mass 25 kg on each wheel, and 7000 kJ of heat was
generated at each wheel help to determine whether these were appropriate for use.
d) Discuss any 3 safety precautions that should be followed to minimize road accidents

The Insurance company only pays back its customers if they are driving within the required speed
limits.

Specific heat capacity of steel brakes is 470 Jkg-lK-1 and their initial temperature is 20 0C

Maximum temperature range for efficient brakes is 600-7000C

Item 54

The vehicle that was hired to transport students for a study tour was equipped with a computer software that
draws the motion of the vehicle from which analysis is made so that refuelling is done. Refuelling is done
based on the distance the vehicle has moved and the driver should refuel every after 210km using reserve
fuel carried in well-sealed jerrycans. The newly employed supervisor of the vehicle is not yet conversant
with the interpretation and analysis of this graph to determine whether the vehicle was indeed refuelled.
Figure 1 shows the motion of the vehicle.

85
 A concise approach to new curriculum physics questions by Buyinza David

During the journey, some students were inconvenienced by the forward and back ward jerking whenever
the vehicle reduced and increased speed suddenly. The students also wondered why despite the vehicle
being closed all the time the interior remained cold

Task: As a student of physics, help the students

(a) Understand why they experienced that kind of movement and how the car interior was kept cold.
(b) Advise the supervisor whether the vehicle was refuelled or not since the fuel was used.

Item 55

The newly employed manager of the motor garage has been advised to take note of all the safety tips and
machine operation procedure in order to avoid accidents.

Figure 2 shows one of the diagrams that shows how one of the machines operate in a garage. A client’s car
of mass 1980kg is being brought to the garage. The manager needs to know how this machine works and if

the effort applied by the worker is enough to lift the car. All the work done by the piston in moving through
the distance AC transforms into heat energy in the liquid. This energy lowers the density of the liquid and if
the temperature changes by 30C and above, the liquid becomes less effective and will be inappropriate for
use in such a machine.
 A concise approach to new curriculum physics questions by Buyinza David

Mass of the liquid when the piston A is in position C = 18 kg

Acceleration due to gravity = 10 ms-2

Specific heat capacity of the liquid = 20 Jkg-1K-1

Task: As a student of physics, help the manager:

(a) Identify the machine and how it works.

(b) Determine whether the liquid being used is appropriate in the stated conditions.

(c) (c) With information that the effort will lift the car of the client.

ITEM 56

Students in a certain school are on a trip in a mountainous area where they are allowed to climb only 500 m
per day. They moved along with a barometer. At a certain place A, the barometer read 69.5 cm Hg, while it
read 75.6 cm Hg at another place B. The students reported that food cooked at point B took longer to get
ready as compared to that at A. This led to an argument between the learners since the food was prepared
with the same amount of fuel. On their first night, learners were warned of the possibility of nose bleeding
during their journey. They were however not sure of which of the points A and B they were most likely to
nose bleed.

Task
Use your knowledge of physics to help the students:

(a) Determine if they had covered the required altitude for the day.

(b) Identify when they were more likely to nosebleed.

87
 A concise approach to new curriculum physics questions by Buyinza David
(c) to understand why the food prepared at B took longer to get ready as compared to that at A.

Item 57

An aluminium pan of mass 800g and specific heat capacity of 800 JKg -1k-1 containing 1.5 kg of ice blocks
at -100 C was accidentally put under a tap producing steam at 1000 C by a house help. After a few minutes,
the ice had all melted and the temperature of the water in the pan was 15 0C. The house help was surprised
by the disappearance of the ice cubes and was tasked to determined how much steam had bubbled into the
saucepan. The house help was tasked to ensure the water does not become warmer without putting it in a
refrigerator.

(Hint; Specific Heat Capacity of water = 4200 JKg -1K-1, Specific Latent Heat of

Vaporization = 3.36 x 106 JKg -1.)

Task

Use your knowledge of physics to;

(a) Determine how much steam was bubbled into the saucepan.
(b) Explain what happened to the ice blocks
(c) Suggest ways in which the water can be kept at that temperature for a long time.
ITEM 58
Of recent, a tall building being constructed in Kampala near Munyoyo collapsed and took very many lives.
When the police tasked the contractor to explain the cause of the collapse, he stated that a client did not
provide enough money to buy the appropriate materials for constructing the building given that the site is
affected by hash weather conditions, however when the KCCA engineer was tasked to Annalise the
situation, he reported building near such sites. The young modulus of steel should be about 2 X 10 11𝑁𝑚-2
His statement confused the public the more.
A force of 500N causes an extension of 20mm on an iron bar of length 100cm whose cross-sectional area is
0.05 𝑐𝑚2
Task As a physics practitioner, you have been tasked by police to produce a report about the scene to help
the police carry out the investigation on the contractor.

ELECTRICITY AND MAGNETISM

Item 1
 A concise approach to new curriculum physics questions by Buyinza David
In a certain place, a house was connected to a 240V mains voltage supply and the owner wished
to connect a TV set rated 120V, 75W, a flat iron rated 120V, 600W, an electric bell of resistance
5 ohms that would instantly produce sound to alert the house owner about the visitors at the gate
when a switch was pressed, and 4 bulbs rated 120V, 60W either in series or parallel connection
for lighting purposes. The house owner also bought a Power King extension with a fuse rated
5A, where he plugged in his TV set and Flat iron. The T.V set is operated for 5 hours per day.

Task:

a) Comment on the effectiveness of the fuse in the extension if it would support the above
electrical appliances when plugged in the extension altogether.

b) Assist the house owner to know in which way to connect his bulbs in the house and
explain why? Explain how sound was produced when a switch was pressed.

c) Determine the amount of money required to keep the T.V operating the whole day, if the
electricity rate is Ug sh. 680 per kWh.

Item 2

In a certain school, students visited a hydroelectric power plant and received information that
electricity at a dam is generated in form of alternating current (a.c) at 12kV but transmitted at
400kV using aluminium transmission cables yet in the physics laboratory electricity can be
generated as direct current (d.c) using dilute sulphuric acid and two electrodes of copper and zinc
where a filament is connected and after sometime its brightness fades. However, learners are
confused about how voltage is increased and have questions how a.c is used to charge a mobile
phone yet it is only d.c that can be used to charge mobile phones.

Task:

a) Explain how voltage is changed from 12 kV to 400 kV

b) Explain how a.c from the dam is used to charge a mobile phone.

c) Determine the current in the transmission cables, if 10% of its energy lost in changing its
voltage, if the current before the change is 20 A

Explain why the brightness of the bulb faded and how it can be restored.

Item 3

89
 A concise approach to new curriculum physics questions by Buyinza David
A factory produces small metallic tanks for storing paint and uses a magnetic lifting device to
move tanks around the factory and packing them in lorries for delivery. One construction
company ordered for large size tanks. However, after manufacturing them, the magnetic lifting
device failed to lift the tanks due to their increased weight. Even the packed tanks were found
attracted to the other. The same day the factory engineer wasn't available which left the
attendants puzzled on how to ensure delivery is made in time.

Support material: A strong electric battery, copper wires, iron rods, current controllers (variable
resistors)

Tasks

As a physics student;

a) Advise the attendants on how and which device they can design to effectively load
them on lorries for timely delivery.

b) Explain how the strength of the device used for loading can be
improved.

c) Explain why is that the tanks were found attracted to each other upon
delivery

d) Advise the construction company on how they will be able to separate the tanks that are
in contact.

Item 4

The welders in a certain workshop are troubled with their tools being shocked by electricity
from a generator of 240V. When they visited a technician, they were advised to wind a copper
wire to 3000 turns around a soft iron ring on the receiving part so as to output 120V suitable for
their work shop operations fixed in a box. However, the welders seem bothered of how this will
be of help.

Task

As a learner of physics,

a) Explain to the welders how the above design will produce power corresponding to their
consumption.
 A concise approach to new curriculum physics questions by Buyinza David
b) Help the welder to determine the number of turns to be would on the output part of the
device. Comment on how efficient the device is if the ratio of current output to current
input is 1.5 A

c) Advise the welders on how to improve the efficiency of the device.

Item 5

A certain household has a set of appliances as listed in the table below.

Appliance Power rating Time of use

4 bulbs 20 each 13 hours every day

Cooker 2500 4 hours every day

Flat iron 1500 5 hours every week

Electric fence of 2200 10 hours every day

low resistance wire

While making the budget, the owner of the household was confused of how much money would be required
every week to cater for the electricity bill. He was also confused on how the sockets for the appliances
should be connected to ensure high current flow and why low resistance wire is used instead of high
resistance wires. The owner intends to spend sh.50000 on electricity every week and each unit of electricity
costs shs.600.

Use the knowledge of physics to;

a) Determine if sh.50000 would be enough to cater for the electricity bill for the week.

b) Explain how the sockets of the appliances should be connected to ensure maximum
current flows. Explain why low-resistance wires are used for the electric fence.

c) Suggest measures on how to reduce the electricity

bill.

Item 6

During a science project, learners are told that electricity at a sub-station is transmitted at 13𝑘𝑉
with a current of 0.05𝐴 using thick aluminium wires for use inside a house at a voltage of 240𝑉.

91
 A concise approach to new curriculum physics questions by Buyinza David
The house has two television sets that operate on direct current but should be connected such that
they receive maximum current and function properly. The learners, however, couldn’t get an
explanation of the issues mentioned.

Tasks

Use your knowledge of physics to;

1. Understand how the voltage is changed from 13𝑘𝑉 to

240𝑘𝑉. Why thick aluminium wires are used during
power transmission.

2. Determine the current in the house if 20% of the electrical energy is lost during voltage
change. Account for the energy losses as the voltage changes and how these losses can be
reduced.

3. Understand how the current used in the TV is changed from alternating current (AC) to
direct current (DC)

4. How the television set should be connected to ensure they receive maximum current and
function properly.

Item 7

Small pieces of metal which are unsafe to be eaten by chicken were found in feeds that had just
been bought from a milling company by a poultry farmer. The small pieces of metal were later
identified as iron. The farmer thought of disposing off the feeds but remembered that the pieces
of metals could be sorted with a magnet which he did not have.

Hint:

A nail connecting wires of resistance 0.5Ω, two dry cells each of 1.5V were available to the
farmer.

Task:

As a student of physics;

a) Help the farmer to remove the pieces of iron from the feeds.

b) Comment on the effectiveness of what you have designed, given that current of 4A is
enough to create a strong magnet.
 A concise approach to new curriculum physics questions by Buyinza David

Item 8

A building has been stuck by lightning, causing damage to its electrical system, including a fuse, a copper wire
used as an earth connection, and a small transformer that was functioning as a voltage regulator. The building’s
owner has decided to replace only the transformer for now and plans to address the fuse and earth connection
later. However, he is uncertain if the newly purchased transformer will perform adequately. The previous
transformer had a power output of over 800W. The building owner has also refused to install a lightning
conductor

Hint

The new transformer is designed to work on 240V, 60W supply. Primary coil has 300 turns and secondary coil
has 200 turns and its efficiency is 80%

Task: as a physics student, you have been requested to explain to the owner of the building

a) How installing a lightening conductor will protect his building

b) Whether the newly bought transformer is suitable for the building’s needs

c) The dangers associated with delaying the replacement of the fuse and re-establishment of a proper earth
connection

Item 9

A business person has started a large-scale business and wants to understand his daily power usage. He also
needs guidance on choosing a generator, saving power and ensuring his workers are knowledgeable wiring
and maintenance.

He has the following electrical instruments

12 security bulbs (5W each) operating 12 hours a day

A 65W refrigerator operating for 24 hours a day

A 3000W juice making machine operating for 5 hours a day

Task

As a student of physics, you have been requested to

a) Assist him to know his daily power usage from the listed electrical instruments

93
 A concise approach to new curriculum physics questions by Buyinza David

b) Choose a suitable generator for his business needs and explain the operation of the chosen generator
with a labelled diagram

c) Describe to his workers the insulator colour codes used in domestic wiring

d) Provide suggestions on how he can save energy

Item 10

In a certain place, electricity is transmitted at 120V. A business person intends to connect 4 bulbs
in a house rated 240V, 60w each and other domestic electrical appliances such that there is
minimum power wastage. The business person has been advised to purchase a transformer of
suitable specifications to achieve the objectives. The business person does not know what a
transformer is, how and is bothered by the type of transformer that should be purchased.

Task: As a student of physics, help the business person to solve the problems he/she is faced with.

Item 11

In your neighbourhood two tenants A and B, living in adjacent rooms but in the same house have
a conflict whenever tenant A switches on her electric stove to start cooking, the bulbs in the
room of the tenant B go dim. This has brought about brought about conflict between the two
tenants.

The conflict has been reported to the land lord who is finding it hard to solve the issue. The land
lord has requested for your help to address the matter.

Task

As a student of physics;

Write an explanation to the landlord on the root cause of this problem.

Using diagrams, suggest a possible solution to the problem.

ITEM 12

One rainy day one of your community members was struck by lightning and his body was having third
degree skin burns and deep wounds. Most community members claimed it was witchcraft, maybe they are
right or there maybe another better explanation to this scenario using knowledge of states of matter.
 A concise approach to new curriculum physics questions by Buyinza David
Task

Explain to the community members what state of matter lightening is giving three more examples
of other substances that fall in the same state of matter as lightening

ITEM 13

During heavy rainstorms, most people seek for shelter under the nearby homestead whereas
others may opt for the following risky measures.

 standing on people’s verandas for fear mostly of getting wet.

 some people however may find themselves on the BODABODA and they just want to
continue with their journey not knowing what risks involved:

 A few people tend to take shelter under the tall trees.

 Some school children even dare to continue enjoying their football games in open soccer
fields still not worried of the risks involved.

 Some people take shelter in very tall buildings which does not have a lightening conductor.

95
 A concise approach to new curriculum physics questions by Buyinza David

As a student of science in the science club of your school, you have been selected to present to the
community meeting during the termly community awareness week of your school. Write a clear well
explained presentation on the possible reasons why the above the mentioned group of people are putting
their lives in danger and in each case suggest the possible preventive measures that can be undertaken to
address/minimize/overcome the dangers you have stated.

Item 14

A S.4 boy has researched about a certain device that produces rotation when connected to a
source of electricity and is found in appliances such as fans, cassette players and disc players.

The boy has removed such a device from an old music cassette player at home and according to
his research it can be converted into a dynamo to light his bicycle’s headlamp. The boy is
looking for assistance on how this can be done.

Task:

a) Help the boy to describe the construction and working of the device to produce rotation.

b) describe how the device is to be converted into a dynamo, and how it will work to light
the head lamp. improve the efficiency of the device.
 A concise approach to new curriculum physics questions by Buyinza David
Item 15

Your neighbour bought an electric kettle and connected it the first time to a power socket to boil
2 kg of water. Immediately, the neighbour heard a small explosion in the kettle and it stopped
working. The neighbour called you for help and on inspecting the kettle, it had the following
features; a two-pin plug connected to the kettle’s cable. The cable had three wires in it, one with
red insulation connected to the first pin, the second with blue insulation, connected to the second
pin and the third had green insulation but not connected to any pin, also, the heating element had
blown. The label on the kettle read 2 kW, 110 V, 50Hz.

Assist your neighbour to:

know the name given to each of the wires in the cable.

a) understand explain the meaning of quantities written on the label.

determine the resistance of the element of the kettle.

b) understand the cause of blowing of the kettle.

c) understand what could have been done to prevent blowing of the kettle.

d) know other precautions that should always be taken in proper use of the kettle.

Item 16

A community has started a project to generate electricity from a nearby water fall. They have
installed a generator that produces 50,000 W of a.c. electricity at 500 V. They hope to transmit
this electricity to the village that is 10 km away. They have erected the poles and connected the

97
 A concise approach to new curriculum physics questions by Buyinza David
necessary wires all the way from the water fall to the village. The wires have a total resistance of
4Ώ . The appliances the community hopes to use work on 240 V. An engineer has advised the
leaders in the project not to connect this power to the users because it will cause problems. The

leaders have disagreed with the engineer, saying that he is using this as a trick to get more money
from him, else they need clear explanations.

Task:

Help the engineer to convince the leaders by;

a) Explaining the problems that will arise if the electricity is used as it is.

b) Determining the percentage power loss that is likely to occur along the way, when the
power is used directly as it is.

c) Explaining the working of the devices that must be installed in the transmission
system to enable safe use of the electricity with minimum power loss.

d) Giving the advantages that the community is to attain by generating a.c. instead
of d.c.

Item 17

A certain home is failing to manage electricity bills and thinks the electricity board is cheating
them. They recently bought 60 units of electricity which got used up in less than a week, even
when they stopped using electricity for cooking food. They also complain that when the lights are
switched on, the rooms in the house become too hot. You inspected their home and found out
that they had 6 filament bulbs of 100 W each that worked 5 hours a day and 3 security lamps of
200 W each that worked 10 hours a day. They were boiling water twice a day with a heating coil
of power 2000 W and it was taking 15 minutes each time to boil water. They wish to get more
information from you after your inspection.

Task:

Assist the members of the home to:

a) Understand the meaning of the number of units they bought.

b) Make necessary calculations to determine whether they were cheated, and give them
any relevant advice.

c) understand why the rooms get hot when their lights are switched on.
 A concise approach to new curriculum physics questions by Buyinza David
d) come up with ways of reducing the electricity bill, even when they are still using it for
same purposes.

Item 18

During a physics study tour to an electricity generation substation, learners were guided on the
processes of electricity generation and consumption. From the information the substation
engineer provided, learners made the following observations which were however not fully
explained because of limited time;

Electricity at the substation is transmitted at 13 kV in alternating current of 0.05 A.

The voltage used for home consumption units is 240 V with a little higher direct current.
Workers in the substation are all required to wear personal protective equipment (PPE).

Task

Using the knowledge of physics, help the learners to:

a) understand why the power is transmitted at a value different from the one
consumed.

b ) determine the exact current supplied to a given home, for consumption how the
voltage changes.

99
 A concise approach to new curriculum physics questions by Buyinza David
c) understand why the substation workers use the PPE?

Item 19

A man constructed his house near a high-power line of 15 KV with 0.08 A. He wanted to connect
the house to the power and use some electrical appliances. He consulted a local electrician who
assured him that they can connect the power line direct to the house in order to reduce costs. The

man was warned by his colleagues that he risks burning down his house if he continues with the
electricians’ plan.

Hint

The man wants to start up with the following appliances in the house:

Item Number of items Power rating Time of use (hours)

Inside bulbs 4 60 W 8

Security bulbs 2 100 W 14

A television 1 120 W 20

A speaker 1 300 W 20

A fridge 1 600 W 4

Task Using the knowledge of physics, help the man to:

Understand;

a) Why his house can easily burn down and explain what he can do to get power
safely. the recommended connection of the bulbs in the house, and why?

b) Determine his weekly expenditure on electricity if the appliances are used daily, taking
the unit cost of the electricity unit as Ug Shs. 550.
 A concise approach to new curriculum physics questions by Buyinza David
c) Know the appropriate practices he needs to adapt which ensure his safety, basing on the
location of his house.

Item 20

On a rainy day, a certain house was struck by lightning, instantly destroying the fuse in the meter
box. The family members were all safe but were advised always to take precautions while it is

raining. The house owner didn’t understand why they needed to take precautions after all no
harm came to them that day.

Hint;

Power supplied to the house through the meter box is 240 V and the fuse is made of a material of
resistance 480 Ω.

Task

Using the knowledge of Physics;

a) Explain to the house owner how he can safe-guard his house from such occurrences in the future.

b) Suggest precautions the family members should always take to be safe when such a
situation arises.

c) Determine the rating of the fuse and the current above which may have caused it to
burn

Item 21

A land-lady was recently told that electricity from a power substation is transmitted at 12 kV
using thick aluminium cables and is to be used in her house at 240 V. She got confused by how
the electricity changes voltage from one value to another and said that the thick cables are a
waste of money. Inside the house are two sets of appliances of resistance 20 Ω and 30 Ω but the
land-lady is not sure of how they should be connected to ensure that they will work effectively.

Use your knowledge of physics to help the land-lady to understand;

a) the system through how the electricity changes from one value to another.

b) why such cables are used.

101
 A concise approach to new curriculum physics questions by Buyinza David
c) how the appliances should be connected to ensure that they work effectively with a high
amount of current.

Item 22

A certain landlord recently finished constructing a block of 2 houses and consulted an electrician to connect
the houses to their electricity grid. The electrician informed him that the voltage of electricity needed to be
stepped down from 13kV to 240V before connecting the houses. The landlord thought the electrician wanted
to cheat him so he decided to hire another person was not qualified to do the job since he was cheaper. The

houses were connected in a way that a breakdown in one house could affect all the houses. The tenants
complained that current was too low and some of their appliances could not work. The tenants have

threatened to vacate the houses if he doesn’t work on the problem. Given that the appliances in the houses
are connected such that the effective resistance in the houses are 10 Ώ and 12 Ώ

Use your knowledge of physics to

a) Explain to the landlord why stepping down voltage is required and how it is done
b) Explain to the landlord the cause of low current in the houses
c) Show with evidence the modifications that could be made to ensure more current flows in the houses

Item 23

A house hold with various appliances (a 3500W cooker used for 4 hours daily, ten 60W lights used for
10 hours daily, and 2500W water heater used for 30 minutes daily) is connected to a 240V mains
supply. The owner struggles to estimate the monthly bill and is uncertain about why an electrician insisted
on the heater being connected to a fuse.

Hint The cost of one unit of electricity is Ush.800

Use your knowledge of physic to;

a) Determine if shs 65000willl be enough for the monthly electricity bill

b) Recommend whether the appliances should be connected in a parallel or in series for better
functionality
c) Explain why the heater should be connected to a fuse

Item 24

Parents are to visit your school on school on science fair day and among things to be exhibited is house
wiring. On the exhibition day, three excited parents approached you with three bulbs labelled 240V,
30W,240V,20W and 240V, 25W whose meaning is not known to them. One parent complains that he had
 A concise approach to new curriculum physics questions by Buyinza David
such bulbs connected in his house and when one bulb blew up, the rest went off but there was electricity as
seen from the main switch and another one with the same type and number f bulbs complained of paying
bigger bill than the neighbour who had three bulbs in the house. The electricity transmitted to your place is
130V

Task

As a student carrying out a science fair on house wiring in physics

1. Help the parents to

a) Understand the meaning of the labels on the bulbs

Know the wiring mistake that made the other bulbs to go off and correct the mistake

2. With explanation, having the problem of low energy supplied to you, assist the parents on how all
the bulbs can work effectively at the same time assuming they are all new. Find the effective
resistance in the whole system
3. Guide the parents on why one of them was paying a bigger bill and advise them on how to avoid it. If
one unit of electricity is shs 950, what is their bill when the bulbs remain on the whole day.

Item 25

A maid at home has just prepared porridge for breakfast and on pulling out the bucket with sugar to mix in
porridge, your two little siblings carrying small iron nails happen to accidentally throw the nails into the
bucket and on rushing to remove, the nails just sunk into the sugar crystals. She is in trouble from your
parents. You start shouting, any magnet but no one has it. In your search, you come across connecting
insulated wires, an iron bar and four tiger head cells in the radio receiver

Hint

Each cell has a P.D of 1.25V and insulated wires have total resistance of 7.5 Ώ

Task

As a student of physics, help the scared maid and siblings

a) To understand the meaning of a magnet

b) To design and describe the system that will solve the problem at hand in absence of a magnet
c) To find the total power supplied to the system

103
 A concise approach to new curriculum physics questions by Buyinza David
d) How to improve the strength of the system because as you try to lift the nails, some of them fall into
the sugar and tell them the necessary precautions that must be taken when you are dealing with such
a setup

ITEM 26

Small metal pieces are dangerous to be eaten by human beings. However, most of the ground nuts paste on
market contains small pieces of these metals from old grinding machines made of iron. Each family is
advised to have a mechanism of removing these metallic pieces.

Hint

You are provided with a nail, connecting wires of total resistance 1.6 Ώ, 2 dry cells each of e.m.f 1.5V and
internal resistance 0.2 Ώ, a double cell holder and an insulated copper wire

Task

As a physics student,

a) Set up a mechanism for sorting the iron pieces from ground nuts

b) Comment on the effectiveness of the designed setup given that current of 2A is enough to create a
strong magnet

c) Suggest how you can make this magnet stronger

Item 27

Your friend, a carpenter, uses an electric drill to drive screws when making furniture. One day the drill he
was using suddenly stopped working. He took the drill to a technician who informed him that the coilin the
d.c motor had got burnt and therefore the motor had to be repaired.

The technician assured your friend that he could repair the motor and make it even more efficient if your
friend brought the required materials. However, your friend couldn’t understand what the technician was
saying and has therefore approached you for more information about structure, mode of operation of the
electric motor and how it can be more efficient

Task

Provide the information needed by your friend

 A concise approach to new curriculum physics questions by Buyinza David
Item 28

A person wants to know how much money he should pay monthly after using the following appliances in his
home. He has an electrical iron rated 240V, 100W, a television set rated 240V, 50W, a fridge rated 240W,
100W and two computers each rated 240V, 50W. he has to determine the size of the circuit breaker needed
to keep these appliances safe

Support: A unit of electricity costs Ugandan shs 500

Task

As a student of physics;

a) help the person to know his monthly bill

b) help the person to size the circuit breaker needed and its importance

c) advise the best way of connecting the appliances for optimal use

Item 29

The school scouts planned to go for a camp where they would stay for seven days. The tent they were to use
had no electrical wiring. The camp site was near a meter box from which they could access electric power
which they would pay for. They intended to wire the tent so as to have electricity

They planned to carry along with them component which they would use to make an electromagnetic device
for alerting members of different activities

The scouts intended to use a bulb rated 240V, 5W for five hours every day and an electric kettle rated 240V,
2Kw for 3 minutes a day. However, on the day of departure, the lead scout who they were relying on to draw
the wiring plan for the tent, design the electromagnetic device, as well as determine the amount of money to
pay for using the bulb and kettle could not be accessed. One of the scouts is your friend and has approached
you for help

Task

Perform the duties of the lead scout

Hint one unit of electricity costs shs 1000

Item 30

A certain team of sailors was navigating along Lake Victoria. The team was involved
in a series of violent storms thunderstorm at the lake. They lost the direction of their

105
 A concise approach to new curriculum physics questions by Buyinza David
journey. Some members thought of sailing any how until they meet the lake shore
while others refused because they knew fuel would get used up before arriving.

Hint: A sewing needle, 2 bar magnets, cork, medium sized bowl and water were
available for the sailors.

Task:

Aa student of physics:

a) Help the sailors to determine the direction for their journey.

b) Comment on the effectiveness of what you have designed.

c) How can sailors stay safe in a thunderstorm?

d) Provide guidance how the bar magnets can be safely stored.

Item 31

In a certain village, electricity is normally supplied at240V and 5A, electricity

normally blacks out on weekends. On working days, a business man normally uses
electricity to charge community batteries and also listens to radio programs. Later his
radio failed to work and he noticed it had specifications 100V,5A and 50Hz, which he
couldn’t interpret, he checked in the empty box of the radio and found two devices
labelled 20Ω and 8Ω which he couldn’t use either. He wishes to work throughout the
week and was advised to purchase a suitable generator of required specifications for
weekend purpose. The business man does not know what a generator is, how it works
and is bothered by the type of the generator that should be purchased.

Hint: The 20Ω and 8Ω devices must be connected either in series or parallel to lower
the input voltage of the radio from 240V to 100V.

Task:

As a student of physics,

a) Describe the specifications of the radio

b) Help the business man to connect the devices to have his radio
working.

c) Advise the business man to solve the weekend problems.

 A concise approach to new curriculum physics questions by Buyinza David
Item 32

A Welder was given a job to make windows of a certain building and he was asked to make
Them from site. On reaching the site he saw a sharp iron bar at the top of the building
being constructed and he wondered why it was put on top of the building.

For his works which he started at 1:00 pm, he had carried a lead-acid battery with him to help
him supply electricity as he was welding. As he was welding, suddenly the battery stopped
producing electricity. He asked the contractor on site if there he can get Direct current (d.c)
power source so that he can re-charge his battery but the contractor got puzzled on how he
was going to do it.

Lead acid battery supplies 50A and has a capacity of 200Ahrs

Task:

As a student of physics, help and explain;

(a) To the welder the use of the bar he saw on the top of the building and how it works.
(b) How the working of the lead acid battery for it to supply power to the welder.
(c) To the contractor how the welder was going to use the d.c power supply
to recharge the battery.
(d) With evidence show when the accumulator suddenly stops supplying
current to the welder.

Item 33

Small pieces of metal which are unsafe to be eaten by chicken were found in feeds
that has just been bought from a milling company by a poultry farmer. The small
pieces of metal were later identified as iron. The farmer thought of disposing off
the feeds but remembered that the pieces of metals could be sorted with a magnet
which he did not have.

Hint:

A nail, connecting wires of resistance 0.5 Ω, two dry cells each of 1.5 V were
available to the farmer.

Task:
107
 A concise approach to new curriculum physics questions by Buyinza David
As a student of physics;

(a) Help the farmer to remove the pieces of iron from the feeds.
(b) Comment on the effectiveness of what you have designed, given
that current of 4 A is enough to create a strong magnet.

Item 34

In a certain place, electricity is transmitted at 120 V. A business person intends to

connect 4 bulbs in a house rated 240 V, 60W each, and other domestic electrical
appliances such that there is minimum power wastage. The business person has
been advised to purchase a transformer of suitable specifications to achieve the
objectives. The business person does not know what a transformer is, how it works
and is bothered by the type of transformer that should be purchased.

Task:

As a student of physics, help the business person to solve the problems he/she is faced with.

Item 35

The manager of a fully constructed estate faces a challenge of high expenditure on

electricity. He hired an electrician to install a circuit breaker which allows a maximum
of 5A to pass through it to restrict electricity supply to appliances. A tenant has a flat
iron rated 240V, 1.1kW, three electric bulbs each rated 240V, 15W, and an electric
kettle rated 240V, 1.5kW. Tiny iron nuts fell into the grass as the electrician was
installing the circuit breaker and he did not have a magnet to pick them.

Hint:

He had an iron rod, copper wires and two dry cells in his tool bag.

Task:

Using the knowledge of physics,

a) help the manager to establish whether the tenant Will be able to use each of
the appliances.
b) Which bulb arrangement do you recommend for the rooms and why?
c) State any other possible solution the manager can adopt to reduce on the challenge.
d) Explain how you could help the engineer to recover his nuts.
 A concise approach to new curriculum physics questions by Buyinza David
Item 36

Your friend's mother complained of high expenditures on electricity bills of last month.
She claims that she is supposed to pay shs.40,000. The mother uses a flat iron for 2
hours, lighting system 12hours, and an electric kettle for 4hours every day. To check
on the electric digital meter, your friend found the readings on the meter as 35847.1 for
the previous month and 35944.4 for the current month. On his way back to the living
room, he accidentally poured tiny iron pins near a copper wire connected to a battery;
and to his surprise, the tiny iron pins were attracted to the wire forming a particular
pattern.

Hint:

A unit of electricity costs shs.700.

Task:

As a learner of Physics, help your friend to;

a) determine if the mother was being cheated on by UMEME.

b) explain to the family how they would avoid high cost of electricity with focus
on the mentioned appliances.
c) understand why the tiny iron pins were attracted to the wire.

Item 37

A certain woman switched on a blender to prepare juice but it could not work. Her friend who had
experienced a similar challenge told her that it was likely to be a Dc motor with a mechanical problem that
needed replacement. She had no money neither did she know what a Dc motor was and how it worked. Soon
as she was still complaining the electricity distribution company brought her a bill of 38950.0shs for the last
month of 30 days which she disagreed with that it was too high compared to what she expected to have used

Appliance No. of appliances Power (W) TIME

Flat iron 1 75 1 hour

Tv 2 100 4 hours

Phone charger 2 50 55 minutes

Lighting bulbs 4 50 2 hours

109
 A concise approach to new curriculum physics questions by Buyinza David

Hint

Mains supply p.d=240V

Cost per unit=shs.950

Task

As a learner of physics

a) Help the woman to explain what a motor is and how it works

b) Advise the woman so that she can appreciate the bill brought to her by the electricity distribution
company

Item 38

A certain house hold has a set of appliances as listed in the table below.

The owner of the household while making a budget for how much money would be required
every week to cater for the electricity bill. He also wondered how the sockets for those
appliances should be connected to ensure high current flows and why low resistance instead of
high resistance wire is used. Hint; The owner only intends to spend sh.50000 on electricity every
week.

Use your knowledge of Physics to;

a) Determine if sh.50000 would be enough to cater for the electricity bill for a week.
b) Explain how the sockets of the appliances should be connected to ensure maximum
current flows
 A concise approach to new curriculum physics questions by Buyinza David
c) Explain why low-resistance wires are used for the electric fence.
d) Suggest measures on how to reduce the electricity bill.

Item 39

An electromagnet as shown in Figure below is constructed by winding a wire around an iron nail
of resistance 0.5Ω, connecting it to a battery of four cells of EMF 1.5V each, and then placing it
above a tin

containing iron fillings, some of which are attracted to the nail. Upon disconnecting the battery,
most iron

fillings fall off. However, when the iron nail is replaced with an identical steel nail of the same size, the pins

are attracted slower. Surprisingly, when the EMF source is disconnected, just a few of the iron
fillings fall

Use your physics knowledge to:

a) Explain how the electromagnet operates.

b) Use domain theory to explain how the nail becomes a magnet.

c) Elaborate on the difference in the time taken before the steel and iron nails start attracting
small pins.

d) Explain what would happen if a battery of 2 cells of the same EMF was used instead of one
of 4 cells. Identify other factors that could contribute to an increase in the number of nails
being attracted.

e) Suggest ways in which the magnetized nails can be made to lose their magnetism.

Item 40

111
 A concise approach to new curriculum physics questions by Buyinza David
In Uganda, domestic electricity is transmitted at 240V. a man has a house in a certain town and uses
electricity. He connected 10 bulbs each withdrawing a current of 4.8A to his house. The bulb lights on an
average of 10 hours a day. He also has a TV set withdrawing a current of 5A which uses on average of 15
hours a day. Also has a flat iron rated 2400W/240V and uses it on average of 2 hours a day.

The Man is disturbed with electricity bills every month. He believes that is being cheated. The man
contacted the board in charge of electricity distribution and was told that the bill was proportional to the
number of units consumed monthly. Each unit costs shs 1000. The man was warned about the dangers of the
main electricity in his house

Task

As a student of physics

a) Help the man understand how to find the number of units he uses monthly and cost if a month is 30
days
b) Help the man understand how he can reduce on his monthly electric costs without reducing on the
number of electric appliances

Help the man understand the safety devices to minimize dangers of main electricity in his house

Item 41

In a certain grinding mill, a worker poured iron fillings into cassava flour as he was packing in small bags.
He had iron fillings he was to take to a certain school. The worker became confused and wondered how he
would sort out the filling from the flour. The worker then remembered that iron could be sorted using a
magnet. He learnt this when n he was in high school. Unfortunately, there was no magnet all around

Hint

Provided with, an iron nail of 6 inch, connecting wires of resistance 3.0 Ώ, four dry cells each of 1.5V and a
switch

Task

as a student of physics,

a) help the worker to remove the iron fillings from the cassava flour
b) if the current of 1.8A is sufficient in your designed method, comment on the effectiveness of what
you have designed
 A concise approach to new curriculum physics questions by Buyinza David
Item 42

A certain home has rooms each with a bulb as shown in the figure

When all bulbs were switched on by members of the rooms at ago to have light, one bulb A did not light but
the other two were found lighting brightly.

Bulb A and the kettle were put in the other rooms and the bulb lit brightly like other two bulbs. The kettle is
considered effective if it is switched on for 4 minutes and 8 seconds.

A member argued that energy from the transformer was not enough. Other members were confused because
they do not know a transformer.

To ascertain all this, l litre of water is filled in the kettle at 15 0C and heated up to 1000C

HINT

Resistance of heating coil of the kettle is 40 Ώ

Specific heat capacity of water is 4200JK-1kg-1

Task

As a learner of physics
113
 A concise approach to new curriculum physics questions by Buyinza David
a) Help the family members understand why the two rooms had light when it was not lighting in the
other room

b) Explain to the home owner what a transformer is and how it works

c) Advise the members whether the kettle was okay or it had a problem

Item 43

During the distribution of hydroelectric power, a certain trading centre remained unconnected
due to cases of electric cables and transformer oils theft. Community members became worried
about relying on solar power during rainy season as majority complain of their phone batteries
being spoilt by solar power. Upon demanding the authorities for the service, they were advised to
purchase a transformer with 100 turns in the secondary coil and 4583 in the primary to supply the
appropriate voltage to run their home equipment but they were concerned that the recommended
transformer would produce insufficient voltage than the one required for house appliances.

Hint:

• All home appliances are rated 220 V—240 V

• Electricity at the substation is transmitted at 11 kV with a current of 0.05 A, using thick aluminum
cables

Task:

Using your knowledge of Physics, help the locals understand:

(a) If the suggested transformer could run their home appliances.

(b) How the transformer recommended works.

(c) Why thick aluminium cables and high voltage are used during power transmission

(d) How a phone charger converts AC to DC to charge the phone batteries

Item 44

A fresh graduate has been employed to work at a printing company and responsibility for maintaining and
optimizing the photocopiers. She has recently encountered a malfunction with the machines but does not
 A concise approach to new curriculum physics questions by Buyinza David
understand the principles of operation of the photocopier however while the technician was investigating the
malfunction in the machine, she realized that motors are applied at the photocopier drum. While testing the
machine, electricity unit was consumed and she wondered a bill of shs.10,000 was used up in just one week
and wondered how much the machine can consume per month so that the bill is always paid once.

Hint:

• The photocopier is rated 220V, 1200W.

• The photocopier machine operates for 9 hours per day on average.

• The cost of electricity is 1,000/=

Task:

As a learner of Physics, help the fresh graduate;

Understand how the principle of electrostatics is used in the operation of the photocopier machine.

Understand how electrical motors in photocopier machine works.

Know the weekly electricity cost of operating the photocopier machine.

ITEM 45

During a visit to an electricity generation substation, learners were told that electricity is transmitted as
alternating current (AC) at 12 kV with a current of 0.05A for use inside a house at a voltage of 240 V. The
learners were however surprised at why the power is transmitted at high voltages. The house has a television
set (TV) that operates on direct current. The learners however, don't understand;

• How the voltage is changed from 13 kV to 240 V.

• The amount of current that flows in the house.

• How the current is changed from Alternating Current (AC) in the wires to direct current (DC) in the TV.

115
 A concise approach to new curriculum physics questions by Buyinza David
Task
Use your knowledge of physics to help the learners;

(a) Understand how the voltage is changed from 13 kV to 240 V.

(b) Determine the current in the house.

(c) Understand how the current used in the TV was changed from AC to DC.

(d) Understand why current is transmitted at high voltages and as alternating current.

Item 46

During a science project, an electromagnet was constructed by winding a wire around a steel nail,
connecting it to an EMF source of 3V, and then placing it above a tin containing small pins, some of which
are attracted to the nail. Upon disconnecting the cells, some nails fall off. However, when the steel nail is
replaced with an iron nail of the same size, the pins are attracted more quickly. Surprisingly, when the EMF
source is disconnected, almost all the nails fell off. The learners wanted to change the EMF source to 8V but
were not sure of what would happen.

(Hint; Resistance of the nails = 0.5 Ω)

Task

Use your physics knowledge to:

(a) Explain how the electromagnet operates.

(b) Explain why there was a difference in the time taken before the steel and iron nails started attracting
pins. Explain what would happen if an EMF source of 8V was used instead of 3V.

Item 47

A community leader who owns a popular village video cinema, is preparing for the upcoming power
blackouts during the scheduled maintenance of the arca transformer. To ensure uninterrupted
entertainment for the villagers, the leader has invested in a diesel-powered AC generator (Figure 1) as
a reliable backup power source.

AC Generator
 A concise approach to new curriculum physics questions by Buyinza David

SlJp
Alternatlng
Carbon

Figure 1: AC Generator

'Ibe cinema hall's equipment and the duration at which they will be switched on is given in
table 2.

Table 2: Cinema Equipment.

Equipment Power (watts) Duration

(hours / day)

Tv 300 14

5
Refrigerator 3000

5 Energy saving bulbs 15 each 12

Loudspeaker 50 8

Automatic electric fan 14

75

Task:

As a physics student;

Regarding the current flow through the sides ABCD of the rectangular coil of the AC generator as shown in
Figure 1.
Explain how an AC generator works.
Use a circuit diagram to explain to the community leader how the automatic electric fan that depends on
temperature installed in the hall works.

117
 A concise approach to new curriculum physics questions by Buyinza David
If the community leader has a budget for fuel Jess than Shs 100,000 for five days. Comment whether the
leader will be able to run the generator for the five days.
Discuss any dangers associated with electricity and suggest the safety precautions.

Hint
For every 0.4 litres of diesel consumed, the generator produces approximately 1.8 kWh of electric
energy

I litre of diesel costs Shs 4950

Item 47.

In the previous rainy season, there was a powerful lightning that was observed striking severely
damaging an arca transformer causing a power shutdown. The team found out that lightning strike led to
a voltage increase in the transformer’s secondary coils well above the standard 240V that is required by
the households. Figure below shows the winding of coils in the secondary and primary coils.

Np=1500 Ns=500 Vs=240V

This unexpected event led to widespread damage, burning out numerous home appliances and
resulting in significant financial losses for the residents. Upon investigating the incident, the
team from the local area electricity distribution company discovered a critical electricity

anomaly. The homes that suffered the most damage had poorly connected or inadequate
earthing systems. Therefore, the team has organized a sensitization program for the citizens
and you as a physics student you are invited to be part of the facilitators.
 A concise approach to new curriculum physics questions by Buyinza David
Task:
As a physics student sensitize the area citizens on;

(a) Suggesting ways on how arca citizens can safeguard themselves from such dangers of
lightning.

(b) Explain the purpose of earthing in their household electrical system?

(c) Several households wish to install automatic electric bulbs that depend on intensity of light.
explain how such bulbs work.

(d) A transformer to be replaced is expected to deliver an output of 20 KW with a primary

current of 28.7 A. Comment whether such a transformer can be recommended as a good one
for use.

(e) discus any two factors that might affect the efficiency of the transformer and suggest ways to
minimize each of them

Hint:
(i) A good ideal transformer should operate at an efficiency of between 95% - 99%

119
A concise approach to new curriculum physics questions by Buyinza David