SCHOO CATHOLIC SCHOOLS ACADEMIC UNION (CASAU)

CANDIDATE NO:
CADEAIC DNTO,
FORM FOUR PRE-NATIONAL EXAMINATION
031/1 PHYSICS 1
(For School Candidates Only)
Time: 3 Hours Year 2021

Instructions
1. This paper consists of sections A, B andC with a total of eleven (11) questions.

2. Answer all questions in sections A and B and two (2) questions from section C.

3. Section A caries fifteen (15) marks, section B sixty (60) marks and section C caries
twenty-five (25) marks.
4. Cellular phones and any unauthorized materials are not allowed in the examination
room.

5. Non-Programmable calculators may be used.

6. Write your Examination Number on every page of your answer booklet(s).

7. Where necessary the following constants may be used:

. Acceleration due to gravity, g= 10 m/s2

ii. Density of water = 1.0 gcm*

ii. Pi, n= 3.14

iv. Radius of the earth r= 6.4 x 10* km.
v. Distance of the earth from sun, R= 1.5 x 10 km.

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 SECTION A (15 Marks)
Answer all questions in this section.

the alternatives and write

.
For each of the items (i) (x), choose the correct answer among given
-

its letter beside the item number in the answer booklet provided.
Measurement of mass by using equal-arm beam balance uses the principle of
.
A. Conservation of momentum.
B. Conservation of energy
C. Moments
D. Gravitational pull of the earth
E. Conservation of matter.
ii. The principle of fluid pressure which is used in hydraulic brakes, is the
A. Pressure is the same at all levels in a fluid
B. Increases of pressure are transmitted equally to all parts of a fluid
C. The pressure at a point in fluid is due to the weight of the fluid above it
D. Increases of pressure can only be transmitted through fluids
E. The pressure at a given depth is proportional to the depth in the fluid.

ii. The surface tension of a fluid dueto

A. Molecules on its surface
B. A semi-permeable membrane which covers it
C. The Brownian motion of surface molecules
D. The cohesive force between its surface molecules
E. The adhesive force between molecules of different materials.
iv. A glass vessel ofvolume 100 cm is filled with mercury and is heated from 25 Cto 75C. What
volume of mercury will overflow? Coeficient of linear expansion of glass =1.8<10PC and
coefficient of volume expansion ofmercury is 1.8x10^/C.
A. 0.67 cm
B. 0.87 cm
C. 0.174 cm*
D. 0.98 cm
E. 0.89 cm
V. Light waves of a given colour from the sun are allowed to pass through different
transparent media. The quantity associated with the wave motion that remains unchanged
throughout the path is..
A. Wavelength
B. Velocity
C. Frequency
D. Amplitude
E. Wave energy
vi. What causes water tides in the sea?
A. Rotation of the earth about the sun
B. Rotation of the moon about the earth
C. Rotation of the earth about its axis
D. Gravitational force due to the earth on the sea
E. Gravitational force due to the moon on the sea.

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 vii. A rod of
insulating material is charged
the latter is tested for positively by rubbing against a piece of fabric and
electric charge. The fabric will be expected to have a...
A. Positive charge equal to that on the rod
B. Positive charge less than that on the
C. rod
Negative charge equal to that on the rod
D. Negative charge greater than that on the
E. Negative charge less than that on the rod rod
vii. Which is an incorrect statement about the solar
A. They always moving in space
are planets?
B. They are all
nonluminous
C. They all revolve
round the sun as their centre
D. They all have at
least one moon
E. The
brightest planet as observed from the earth is
ix. venus.
Which one is not a
A. Radio waves
region of electromagnetic spectrum?
B. X-rays
C. Infrared light
D. Ultraviolet light
E. Invisible
light waves.
X. What makes a coin inside the
from above? water at the bottom of a
vessel appear to rise when
viewed
A. Reflection of light.
B. Refraction of light.
C. Mirage of light.
D.
Spectrum of light.
E. Diffraction of light
2. Match the times in List A with
booklet provided.responses
in the answer in List B by writing the letter
of the correct
response
LIST A
i. An instrument that LIST B
detects the
current. presence of electric A. Galvanometer
ii. An instrument B. Voltmeter
that measures the
across a wire. potential diferences C. Ammeter
ii. A device which
protects an electric circuit D. Rheostat
excess current. against
E. Potentiometer
iv. An instrument designed to
produce variable resistance. F. Resistor
V. An instrument that
detects small electric
charges. G. Spectrometer
H. Gold
leaf Electroscope
Circuit breaker
J. Fuse

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 SECTION B (60 Marks)
Answer all questions in this section.

3. (a) Using Newton's second law of motion, state two quantities which vary with net
force applied on a body. (1 Mark)
(6) Write an equation obtained by combining the force and the two quantities you have
mentioned. (2 Marks)
(c) Evaluate the proportionality constant if your equation is used to define the unit of force, the
Newton, while taking a unit of each variable in your equation. (3 Marks)
(d) A certain force gives a mass mi an acceleration of 12.0 m/s?. What acceleration will the
same force give two similar masses when they are joined together? (4 Marks)
4. (a) State Boyle's law.
(2 Marks)
(b) Sketch the graph of pressure (P) against the reciprocal of volume (V-1) for air at
constant temperature. (3Marks)
(c) A bubble of air of volume 50.0
mm
is released by a diver at a depth where the pressure
is
304.0 cmHg. Assuming the temperature remains constant, what is its volume just before it
reaches the surface where the pressure is 76.0 cmHg? (5 Marks)
5. (a) Explain what is meant by 'beats' as applied to sound.
(2 Marks)
(b) Briefly explain how beats are formed. (2 Marks)
()Avibrating string is sounded with a 288 Hz tuning fork and 3 beats are counted per second.
The string is then loaded with small amount of plasticine and 2 beats are counted per
second.
() What is the frequency of the string? (3 Marks)
i) What is the frequency of the loaded string? (3 Marks)
6. (a) Name two objects in space which are the earths nearest neighbors. 1 Mark)
(6) What are the real names of objects in the sky which are commonly known by the following
names?

) An evening star (1 Mark)

i) A morning star ( Mark)
(ii) A shooting star (1 Mark)
()The earth appears to be stationary, but it is always in motion. Calculate the unnoticed speed
of a man along the equator, in km/h due to;

(). Rotational motion of the carth about its axis 3 Marks)

Gi). Revolution of the earth around the sun. Take 1 year = 365 days 3 Marks)
7. (a) State Pascal's principle of transmission of pressure. (2 Marks)

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 force
section area of 30.0 cm2 is used in hydraulic
press to exert a
(b) A piston of small cross
leads to a large piston of
cross

of 300.0 N on the enclosed liquid. A connecting pipe

sectional area 600.0 cm. Find
(3 Marks)
The force sustained by the larger piston
(i)
2.0 tonnes on the larger piston
(i) the force applied on the smaller piston support
to
(3 Marks)

the pistons of the press. (2 Marks)

(ii) the mechanical advantage (MA) of
prism. (2 Marks)
8. (a) () Explain what happens when a light is incident on a triangular glass
white

refraction in the glass if light is

incident in the air at 40° on a
(i) Calculate the angle of
of 1.52. (2 Marks)
plane glass surface of refractive index stand for
fby using the mirror formula where, m
(b) Derive an expression, u ( =

magnification of the image formed and other symbols carry their usual meaning.
(3 Marks)
40 cm. How far from the mirror must
an object be
A concave mirror has a focal length of
(c) (3 Marks)
twice the size of the object.
placed to produce an image that is

SECTIONC(25 Marks)
Answer two (2) questions from this section.

and insulators in terms of their

9. (a) Distinguish the concepts of conductors, semiconductors
(6 Marks)
energy bands.

electric circuit. Carefully study it and calculate the value of current x

(b) Figure 1 shows an (4 Marks)

andr.

52A12A 400

Figure 1

resistance. (2.5 Marks)

(c)From part (b), determine the effective
instead of being in one soiid
10. (a) Why is the iron core of a transformer made of laminations (2.5 Marksj
piece?
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 6) A transformer is used on the 240 V a.c supply to deliver 8 A at 90 Volts to a heating coil
calculate.

i) the current in the primary winding (3 Marks)

i) the power in the secondary windings (3 Marks)

(c) If the primary current is used to light 25 12 V, 24 W ray lamps what is the efficiency of the
transformer? (4 Marks)
11. (a) Complete the table belowfor the three particles which are emitted in a nuclear decay
process. (4 Marks)
Type of particle Charge on the Position of daughter nuclide in Effect on mass number
emitted particle Periodic Table with respect to of parent nuclide after
parent nuclide emission

Alpha(a)
Beta ()

Gamma (Y) No effect

Part of certain nuclear decay series is represented by the following unbalanced

b) a

equations, in each stage only ONE type of particle is emitted.

() Th232 Ran8
1) 8Ra223 *Ac28
(iii) Acza8®Th228
(iv) Thz2s Ra24 (2 Marks)
Write two pairs of isotopes from the above series (2 Marks)
(c)
half-life of the isotope Cobalt-60 is 20 days. Use the graph to estimate the remaining
(d) The
mass at the 70h day if its initial mass is 0.64 g. (4.5 Marks)

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