(Paper) Model Questions for Engineering Entrance Tests Part - 1

Model Questions for Engineering Entrance Tests Part - 1
( Physics) 

1. 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
Ans: B

2. 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
Ans: A

3. Sound is propagated in air as
(a) Stationary waves
(b) Longitudinal waves
(c) Transverse waves
(d) Standing waves
Ans: B

4. 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
Ans: B

5. 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
Ans: C

6. 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
Ans: A

7. 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
Ans: E

8. 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
Ans: A

9. The meniscus of mercury in a glass tube is
(a) concave
(b) plane
(c) convex
(d) horizontal
Ans: C

10. 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
Ans: B

11. 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
Ans: A

12. 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
Ans: C

13. 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
Ans: C

14. 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
Ans: B

15. 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
Ans: C

16. 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
Ans: B

17. Hydrogen has
(a) One isotope
(b) Two isotopes
(c) Three isotopes
(d) None of the above
Ans: C

18. 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
Ans: A

19. 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
Ans: D

20. 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
Ans: D

21. 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
Ans: A

22. 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
Ans: D

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

24. Which of the following particles is unstable
(a) Proton
(b) Alpha particle
(c) Neutron
(d) Electron
Ans: C

25. 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
Ans: E

26. 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
Ans: A

27. 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
Ans: E

28. The thermocouple cannot act as
(a) Thermometer
(b) Voltmeter
(c) Refrigerator
(d) a.c generator
Ans: D

29. 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
Ans: A

30. 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
Ans: B

31. 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
Ans: A

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

33. 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
Ans: D

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

35. 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
Ans: B

36. 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
Ans: C

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

38. 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
Ans: B

39. 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]
Ans: D

40. 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
Ans: E

41. 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
Ans: D

42. 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
Ans: D

43. A possible fuel for nuclear reactors is
(a) Lead
(b) Plutonium
(c) Berrylium
(d) Zirconium
Ans: B

44. 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
Ans: C

45. For an adiabatic charge
(a) ∆u = 0
(b) ∆Q = ∆w
(c) ∆w = 0
(d) ∆u = −∆w
Ans: D

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

47. 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
Ans: A

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

49. 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
Ans: D

50. 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
Ans: C