CPMT Sample Paper Physics

1. In the photocells
(a) light is converted to heat
(b) electrical energy is converted to light energy
(c) light energy is converted to electrical energy
(d) heat is converted to light

2. The acceleration of an object moving in a straight line is equal
to the
(a) Slope of the displacement - time graph
(b) Area under velocity - time graph
(c) Area under displacement - time graph
(d) Slope of the velocity - time graph

3. The dimensions of angular momentum are
(a) MLT―1 (b) ML―1T (c) ML2T―1 (d) MLT―2

4. The temperature above which a gas cannot be liquefied by the
application of mere pressure is called
(a) Critical temperature (b) Boiling point
(c) Boyle temperature (d) Freezing point

5. In a closed tube, the frequencies of the overtones are .....
multiplies of the fundamental
(a) Even (b) Odd (c) Sub (d) Integral

6. For an adiabatic charge
(a) ∆u = 0 (b) ∆Q = ∆w (c) ∆w = 0 (d) ∆u = −∆w

7. A monoatomic ideal gas initially at 170C is suddenly compressed
to one eighth of its original volume. The temperature after
compression is
(a) 170C (b) 1360 C (c) 8870C

8. A possible fuel for nuclear reactors is
(a) Lead (b) Plutonium (c) Berrylium (d) Zirconium

9. The transformer of an audio amplifier has out put impedance
8000Ω and the speaker has input impedance of 8Ω, the ratio of
primary to secondary turns of this transformer connected
between the out put of amplifier and to loud speaker should have
the ratio
(a) 1000:1 (b) 100:1 (c) 1:32 (d) 32:1 (e) 1:1000

10. A charged oil drop of mass 9.75×10-15 kg and charge
30×10-16C is suspended in a uniform electric field existing
between two parallel plates. The field between the plates,
taking g=10ms-2, is
(a) 3.25 v/m
(b) 300 v/m
(c) 325 v/m
(d) 32.5 v/m
(e) 3000 v/m

11. A dim star magnitude +14.5 explodes into a nova of magnitude
+2. The factor by which the brightness of the star has
increased is
(a) 12.5 (b) 102 (c) 103 (d) 104 (e) 105

12. If the velocity of light c, gravitational constant G the Plank's
constant h are chosen as fundamental units, the dimension of
length L in the new system is
(a) [h1 c1 G-1]
(b) [h1/2 c1/2 G-1/2]
(c) [h1 c-3 G-1]
(d) [h1/2 c-3/2 G1/2]
(e) [h1 c0 G0]

13. 92U238 decays successively to form 90Th234, 91Pa234, 92U234,
90Th230 and 88Ra226 then during the reaction the number of
particles emitted is
(a) 4 (b) 3 (c) 5 (d) 2 (e) 1

14. Out of the following electromagnetic radiations, which has the
shortest wavelength?
(a) radio waves
(b) infrared
(c) ultraviolet
(d) visible light
(e) X-rays

15. Heavy water is one of the substances used as moderator in
reactors. Which of the following is also used as moderator?
(a) Sea water (b) Cobalt (c) Graphite (d) Titanium

16. Water is used in hot water bottles because:
(a) water is not harmful to human body
(b) water has high specific heat
(c) water is easily available
(d) it is not easy to heat water

17. Maxwell in his famous equation of electromagnetism introduced
the concept
(a) AC current
(b) DC current
(c) displacement current
(d) impedance
(e) reactance

18. In a property biased transistor
(a) both depletion layers are equally large
(b) both depletion layers are equally small
(c) emitter-base depletion layer is large but base-collector
layer is small
(d) emitter-base depletion layer is small but base-collector
depletion layer is large
(e) both depletion layers vanish

19. The graph between acceleration and time for the particle in
SHM is
(a) Sinusoidal (b) Parabola (c) Straight line (d) Ellipse

20. When a vibrating turning fork is placed on a sonometer, a large
sound is heard. This is due to
(a) Forced vibration (b) Reflection of sound
(c) Beats (d) Resonance

21. A liquid boils when its vapour pressure is
(a) greater than total external pressure on its surface
(b) equal to total external pressure on its surface
(c) equal to atmospheric pressure
(d) less than total external pressure on its surface

22. The mean orbital radius of planet Pluto is 6 tera-meters. Then
the orbital radius in terms of mega meters is
(a) 6×106 (b) 6×105 (c) 6×109 (d) 6×108

23. The thermocouple cannot act as
(a) Thermometer (b) Voltmeter
(c) Refrigerator (d) a.c generator

24. A ball hangs from a string inside a train moving along a
horizontal straight track. The string is observed to incline
towards the rear of the train making a constant small angle
with the vertical. It shows that the train is
(a) moving with a uniform acceleration
(b) moving with a uniform velocity
(c) moving with a uniform retardation
(d) moving with an acceleration which is increasing uniformly
(e) at rest

25. In a n-p-n transistor amplifier, the collector current is 9mA. If
90% of the electrons from the emitter reach the collector, then
(a) α = 0.9; β = 9.0
(b) the base current is10mA
(c) the emitter current is 1mA
(d) α = 9.0; β = 0.9
(e) α = 0.99; β = 99.0

26. The power of combination of a convex lens of focal length
50 cm and concave lens of focal length 40 cm is
(a) +1 diopter
(b) -1 diopter
(c) 0
(d) +0.5 diopter
(e) -0.5 diopter

27. Which of the following particles is unstable
(a) Proton (b) Alpha particle (c) Neutron (d) Electron

28. The gas law PVγ constant is true for:
(a) Adiabatic changes only (b) Isothermal changes only
(c) Both isothermal and adiabatic changes

29. When light wave travels from one medium into another its
(a) Velocity, frequency and wave length does not change
(b) Velocity does not change
(c) Wavelength does not change
(d) Frequency does not change

30. The apparent change in frequency due to relative motion
between source of sound and a listener is called
(a) Doppler effect (b) Diffraction
(c) Resonance (d) Beat phenomenon

31. A lump of ice floats in water in a beaker. When all the ice
melts, the level of water in the beaker will
(a) go down (b) change (c) rise (d) remain unchanged

32. A plate has a length 5.00 ± 0.10cm and breadth
2.00 ± 0.01 cm. Then the area of the plate is
(a) 10 ± 0.1 cm2
(b) 10.0 ± 0.01 cm2
(c) 10.0 ± 0.25 cm2
(d) 10.0 ± 0.2 cm2
(e) 10 cm2

33. Two coherent sources whose intensity ratio is 81:1 produce
interference fringes. The ratio of minimum to maximum intensity
i.e: Imin : Imax is
(a) 16.25 (b) 9:1 (c) 1:9 (d) 25:16 (d) 5:4

34. Hydrogen has
(a) One isotope (b) Two isotopes
(c) Three isotopes (d) None of the above

35. A thin circular brass disc has a concentric hole through it so as
to make it a washer. It is then heated. Owing to expansion of
metal, the diameter of the hole will:
(a) decrease (b) increase (c) remain the same

36. A body is projected so as to have a maximum range of 80m.
The wrong statement about this motion is/are
(a) its angle of projection is 450
(b) its vertical height is 20m
(c) its energy is zero at the highest point
(d) its path is a parabola

37. Image formed by a convex lens is virtual and erect when the
object is placed
(a) at F
(b) between F and the lens
(c) at 2F
(d) beyond 2F
(e) at infinity

38. What enables the aeroplane to rise in air?
(a) The lifting capacity of a downward jet of air
(b) The lifting capacity of an upward jet of air
(c) The low pressure above the wings
(d) The high pressure above the wings

39. If the sun becomes twice as hot
(a) the output of radiated energy will be eight times larger
(b) it will radiate predominantly in the infrared
(c) it will radiate predominantly in the ultraviolet
(d) the output of the radiated energy will be eight times smaller
(e) the frequency spectrum of the radiated energy will not alter

40. Let the potential energy of electron in hydrogen atom in the
ground state be regarded as zero. Then its potential energy in
the first excited state will be
(a) 20.4 eV (b) 13.6 eV (c) 3.4 eV (d) 6.8 eV (e) 10.2 eV

41. In the electromagnetic spectrum, the visible spectrum lies
between
(a) radio waves and microwaves
(b) infra red and ultraviolet rays
(c) micro waves and infra red spectrum
(d) X- ray and gamma ray spectrum
(e) ultraviolet and X ray spectrum

42. The meniscus of mercury in a glass tube is
(a) concave (b) plane (c) convex (d) horizontal

43. Energy in the Sun is generated mainly by
(a) Fusion of hydrogen atoms (b) Chemical reaction
(c) Fission of helium atoms (d) Fusion of radioactive material

44. In Young's double slit experiment, the width of one of the slits
is lowly increased to make it twice the width of the other slit.
Then in the interference pattern
(a) the intensity of maxima increase while that of minima
decrease
(b) the intensities of both maxima and minima decrease
(c) the intensities of both maxima and minima remain the same
(d) the intensity of maxima and decrease while that of minima
increase
(e) the intensities of both maxima and minima increase

45. Frequency of characteristic X-rays depends on
(a) atomic number of target (b) mass number of target
(c) accelerating p.d applied (d) kinetic energy of electron

46. Two radioactive nuclides x and y have half lives 1 hour and
2 hours respectively. Initially the samples have equal number of
nuclei. After 4 hours the ratio of the numbers of x and y is
(a) 1/2 (b) 2 (c) 1/4 (d) 1 (e) 1/16

47. Surface tension of water is 0.072 Nm−1. The excess pressure
inside a water drop of diameter 1.2 mm is
(a) 0.086 Nm−2 (b) 240 Nm−2 (c) 120 Nm−2 (d) 72 Nm−2

48. Sound is propagated in air as
(a) Stationary waves (b) Longitudinal waves
(c) Transverse waves (d) Standing waves

49. If the wavelength of incident light changes from 400 nm to
300 nm, the stopping potential for photoelectrons emitted from
a surface becomes approximately
(a) 1.0 volt greater
(b) 1.0 volt smaller
(c) 0.5 volt greater
(d) 0.5 volt smaller
(e) 0.1 volt greater

50. Which is the only vector quantity out of the following?
(a) Electrostatic potential
(b) Moment of a spinning body
(c) Current flowing in a metal
(d) Charge of a gold leaf electroscope

Answers

1 C 11 E 21 B 31 D 41 B
2 D 12 D 22 A 32 D 42 C
3 C 13 B 23 D 33 A 43 A
4 A 14 E 24 A 34 C 44 E
5 B 15 C 25 A 35 B 45 A
6 D 16 B 26 E 36 C 46 C
7 C 17 C 27 C 37 B 47 B
8 B 18 D 28 A 38 C 48 B
9 D 19 A 29 D 39 C 49 A 10 D 20 A 30 A 40 A 50 B