SRI VISHWESHWARAIAH SCHOOL
(Affiliated to ICSE Board, New Delhi, No: KA-129/2007)
Date : 20.12.23 FIRST PRELIMS EXAM - 2023-24 Class: X
4
PHYSICS
(SCIENCE PAPER 1)
Maximum Marks: 80
Time allowed: Two hours
Answers to this Paper must be written on the paper provided separately
You will not be allowed to write during the first 10 minutes.
This time is to be spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section A is compulsory. Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
SECTION A (40 Marks)
(Attempt all questions from this section)
S
Question-1 [15 x 1 = 15]
Choose the correct answers to the questions from the given options.
i) Bowls of different diameters are filled up to different levels of water while playing Jal tarang because
a) They look beautiful
b) They create a good ambience
c) Different sounds are produced due to air column
d) It is the characteristic of that musical instrument
ii) The frequency of four notes is, Which of these notes have the lower pitch.
a) A = 256HZ
b) B = 120HZ
c) C = 512HZ
d) D = 400HZ
iii) Ohm’s law is the relationship between ______ and ___________
a) Pressure, volume
b) Volume, temperature
c) Voltage, current
d) Resistance, current
iv) The rating of a fan is 80W-250V the current flowing through is
a) 0.32A
b) 03.12A
c) 25.6A
d) None of these
v) Fuse wire is made of an alloy of
a) Iron & tin
b) Copper and lead
c) Tin & lead
d) Copper and iron
vi) Plug and socket should not be touched with _________ hands
a) Dry
b) Wet
c) Clean
d) Dirty
T24 - PRELIMS 1 1 of 6
vii) The turns ratio in a step up transformer is
a) Less than 1
b) Greater than 1
c) Equal to 1
d) Could be any of these
viii) The rule that helps to find the direction of force acting on a current corrying conductor is
a) Lenz’s law
b) Right Land thumb rule
c) Fleming’s right hand rule
d) Fleming’s left hand rule
ix) Heating curve has a ______ slope
a) Positive
b) Negative
c) Constant
d) None of these
x) During change of physical state temperature
a) Changes
b) Varies
c) Remains constant
d) Becomes zero
xi) The fragments formed in nuclear fission U-235
a) Potassium and Barium
b) Calcium and krypton
c) Barium & krypton
d) Argon & neon
xii) One atomic mass unit is equivalent to an energy of
a) 9.31mev
b) 1 Mev
c) 931 Mev
d) 931 ev
xiii) With reference ot the adjoining fig if RP is 5Ω then what is the value of R3=?
a) 3 Ω
b) 30 Ω
c) 0.3
d) None of these
xiv) With reference to the adjoining fig. Name the characterstic of sound:
a) Pitch
b) Loudness
c) Quality
d) Intensity
T24 - PRELIMS 1 2 of 6
xv) Which is the correct statement with reference to diagram
a) Slope A is in series
b) Slope A is in parallel
c) Slope B is in parallel and high temperature
d) Slope B is parallel
Question 2
i) a) An echo is heard in 3s after the emission of sound. If the speed of sound in air is 340m S-1. 2M
What is the distance of the reflecting surface from the source?
b) What is an echo? State one condition for an echo to take place. 2M
ii) A Geyser rated 1.5kw, 250v it is connected to 250v mains. 3M
a) Calculate the current drawn by the Geyser
b) Electrical energy consumed in 10h in joules
c) Cost of energy consumed at ₹3.50 per kwh.
iii) With reference to the adjoining diagram answer
the following questions
a) In which direction will the needle deflect when the 3M
key is closed
b) What will be the change in the deflection if the
magnetic needle is taken just above the conductor AB
c) Name one device which works on this principle
iv) A Metallic wire of length 1m is stretched to double its length in such a way that there is no change in
density of the wire calculate the ratio of initial and final resistance. 1M
v) a) Complete the following nuclear changes 2M
→ →
b) How beta particles are emitted from the nucleus 1M
Question 3
a) With reference to the adjoining diagram answer the
following questions.
i) What is the purpose of wooden lid
ii) Why the glass wool is placed in between vessel and wooden jacket
iii) Why copper is preferred as metal in calorimeter
b) i) To raise the temperature of a substance by 150C, the amount of heat energy required is 350J
calculate the heat capacity of the substance. 2M
ii) State one difference between Heat capacity and specific heat capacity 1M
iii) How Heat capacity and specific heat capacity are related? 1M
c) i) State two factors that internal resistance of a cell depends? And also write how
are they depend. 2M
ii) What is the limitations of Ohm’s law. 1M
T24 - PRELIMS 1 3 of 6
SECTION – B
Answer any four questions from this section
Question 4
i) a) What is the principle on which Sonar is based on ? 1M
b) Calculate the minimum distance at which a person should stand in front of a reflecting surface
so that he can hear a distinct echo. (Take speed of sound in air 350ms-1) 2M
ii)a) Name the subjective property
1) on sound related to its frequency
2) of light related to its wavelength. 2M
b) The two waves of the same pitch have their amplitudes in the ratio 2:3
1) What will be the ratio of their loudness? 2M
2) What will be the ratio of their frequencies?
iii) The diagram shows below the displacement – time graph for a vibrating body.
1) Name the type of vibrations produced by the vibrating body
2) Give one example of a body producing such vibrations.
3) Where can a body execute such vibrations? 3M
Question 5
a) Study the diagram carefully and calculate 3M
1) The equivalent resistance between P and Q
2) The reading shown by ammeter
3) The electrical power between P & Q
b) i) What is an ohmic resistance? 3M
ii) Two copper wires of same length but one is thicker than the other
1) Which wire will have more resistance
2) Which wire will have more specific resistance?
c) i) A wire of uniform thickness with resistance of 27Ω is cut into three equal pieces and they are
joined in parallel. Find the resistance of the parallel combination. 2M
ii) An electric heater is rated 750 W-200v. calculate
1) resistance of the heating element
2) Current flowing through it
Question 6
i) a) An kettle is rated as 2.5kw – 250v. find the cost of running the kettle of two hours at ₹6 per unit. 2M
b) State the purpose of a fuse wire in a electric circuit. Name the material required for making a
fuse wire. 2M
ii) a) Which part of an electric appliance is earthed
b) State a relation between electrical power, resistance and potential difference in an electrical circuit
c) In what unit does the domestic electric meter measure the electric energy consumed? 3M
T24 - PRELIMS 1 4 of 6
iii) The diagrams (a) and (b) given below are of a plug and a socket with arrows marked as. 3M
1, 2, 3 and 4, 5, 6 respectively on them. Identify and write Live
(L), Neutral (N) and Earth (E) against the correct number.
Question 7
i) The figure below shows an electromagnet 3M
a) What will be the polarity at the end X?
b) Suggest a way by which the strength of the electromagnet referred to in the question, may be increased.
c) Give one advantage of an electromagnet over a permanent magnet.
ii) a) A straight wire conductor passes vertically through a piece of cardboard spinkled with iron filings. Copy
the diagram and show the setting of iron filings when a current is passed through the wire in the upward
direction and the cardboard is tapped gently. Draw arrow to represent the direction of the magnetic field
lines. 2M
b) Name the law which helped you to find the direction of the magnetic field lines. 1M
iii) a) A device is use to transform 12V AC to 200 V AC
1) What is the name of this device?
2) Name the principle on which it works. 2M
T24 - PRELIMS 1 5 of 6
iv) With reference to the diagram answer the following questions. 2M
i) What is the function of split rings
ii) State one way to increase the speed of the DC motor
Question 8
i) a) What is the method of mixture?
b) What is the other name given to it?
c) Name the law on which the principle is based? 3M
ii) A substance is in the form of a solid at 00C. The amount of heat added to this substance and the
temperature of the substance are plotted on the following graph:
If the specific heat capacity of the solid substance is 500 J/kg0C, find from the graph:-
a) The mass of the substance:
b) the specific latent heat of fusion of the substance in the liquid state: 4M
iii) a) What happens average kinetic energy of the molecules as ice melts to form watered at 00C 1M
b) What you mean by the statement specific heat capacity of copper is 400J kg-1 k-1 2M
Question 9
i) a) What is radioactivity? 1M
b) Mention any two differences between nuclear energy and chemical energy. 2M
c) When does the nucleus of an atom become radioactive? 1M
ii) a) Give one source of background radiation 1M
b) Mention one use and one harmful effect of radioactivity. 2M
iii) a) Complete the following nuclear change. 2M
1) →
2) →
b) Out of alpha, beta and gamma radiations which is more penetrating 1M
PHYSICS THE BASIC SCIENCE ONE CAN EASILY ARGUE THAT ALL OTHER
SCIENCES ARE SPECIALIZED ASPECTS OF PHYSICS
T24 - PRELIMS 1 6 of 6
