PU CET PG 2017 Question Paper MSc_HS__PhysicsMedical PhysicsPhysics _ Electronics_

MSc(HS)(Physics/Medical Physics/Physics & Electronics)

1. A single point charge is situated at the origin and creates an electric field . It follows from the
electrostatics that:
A. ∇ =0
B. ∇ =1
C. ∇ ⋅ = 0
D. ∇ ⋅ = 4
2. The deuteron is formed by a pair of proton and neutron. The reduced mass of this two body
system will:
A. depend on the strength of the strong force.
B. depend on the strength of the weak force.
C. depend on the strength of the gravitational force.
D. not depend on the interaction between them.
3. A neutron collides with another neutron at rest. After collision the angle between the scattered
and the recoil neutrons will be:
A. 00.
B. 900.
C. 1200.
D. 1800.
4. An object moving at constant velocity in an inertial frame must:
A. have a net force acting on it.
B. have no frictional force acting on it.
C. have zero net force acting on it.
D. not have any force of gravity acting on it.
5.The center of mass of a system of particles has a constant velocity if:
A. the forces exerted by the particles on each other sum to zero.
B. the external forces acting on particles of the system sum to zero.
C. the velocity of the center of mass is initially zero.
D. the center of mass is at the geometric center of the system.
6. The acceleration of a comet in an elliptical orbit about the Sun:
A. increases while it is receding from the Sun.
B. is constant.
C. is greatest when nearest from the Sun.
D. varies sinusoidally with time.
7. The amplitude and phase constant of an oscillator are determined by:
A. the frequency.
B. the initial displacement alone.
C. the initial velocity alone.
D. both the initial displacement and the velocity.
8. A sinusoidal force with a given amplitude is applied to an oscillator. At resonance the
amplitude of the oscillation is limited by:
A. the damping force.
B. the initial velocity.
C. the initial amplitude.
D. the force of gravity.
9. The sum of two sinusoidal travelling waves is a sinusoidal travelling wave only if :

A. their amplitudes are the same and they travel in the same direction.
B. their amplitudes are the same and they travel in the opposite direction.
C. their frequencies are the same and they travel in the same direction.
D. their frequencies are the same and they travel in the opposite direction.
10.Two separated sources emit sinusoidal travelling waves that have the same wavelength λ and
are in phase at their respective sources. One travels a distance ℓ1 to get to the observation
point while the other travels a distance ℓ2. The amplitude is a maximum at the observation
point if ℓ1 - ℓ2 is :
A. an odd multiple of λ /2.
B. a multiple of λ .
C. an odd multiple of λ /4.
D. an odd multiple of π /2.
11. The mean free path of molecules of a gas contained in a vessel is proportional to :
A. the molecular diameter.
B. the reciprocal of the molecular diameter.
C. the molecular concentration.
D. the reciprocal of the molecular concentration.
12. The change in entropy is zero for:
A. reversible adiabatic processes.
B. reversible isothermal processes.
C. reversible isobaric processes.
D. reversible processes during which no work is done.
13. Un-polarized monochromatic light is incident on a polarizer. A quarter-wave plate is placed
after the polarizer so that the polarizer axis is at 450 to the two axes of the quarter-wave plate.
The emerging light from the plate will be:
A. un-polarized.
B. circularly polarized.
C. plane polarized.
D. elliptical polarized.
14. An electric field exerts a torque on a dipole only if:
A. the field is parallel to the dipole moment.
B. the field is not parallel to the dipole moment.
C. the field is perpendicular to the dipole moment.
D. the field is uniform.
15. Magnetization is :
A. the current density in an object.
B. the charge density of moving charges in an object.
C. the magnetic dipole moment of an object.
D. the magnetic dipole moment per unit volume of an object.
16. The spin magnetic dipole moment of an electron:
A. is zero.
B. is in the same direction as the spin angular momentum.
C. is in the opposite direction of the spin angular momentum.
D. has magnitude that depends on the applied magnetic field.
17.A magnetic field B0 is applied to a diamagnetic substance. In the interior the magnetic field
produced by the magnetic dipoles of the substance is:
A. greater than B0 and in the opposite direction.

B. less than B0 and in the opposite direction.
C. greater than B0 and in the same direction.
D. less than B0 and in the same direction.
18. Because ferromagnets exhibit hysteresis, the magnetization:
A. can never vanish.
B. can never be in the same direction as an applied field.
C. may not vanish when an applied field is reduced to zero.
D. is proportional to any applied magnetic field .
19. A magnetic field exists between the plates of a capacitor:
A. always.
B. never.
C. when the capacitor is fully charged.
D. while the capacitor is being charged.

20. One of the Maxwell equation is ∮ .d = 0. The infinitesimal vector area d is always:
A. tangent to surface.
B. perpendicular to the surface and pointing outward.
C. perpendicular to the surface and pointing inward.
D. tangent to a field line.
21. The rms value of a sinusoidal voltage is V0/ √2 where V0 is the amplitude. What is the rms
value of its fully rectified wave?
A. V02 / √2.
B. V02 / 2.
C. √2 V0.
D. V0 / √2.
22. A charged capacitor and an inductor are connected in series. At time t = 0 the current is zero. If
T is the period of the resulting oscillations, the next time, after t = 0 that the current is a
maximum is :
A. T.
B. T/4.
C. T/2 .
D. 2T.
23. The time averaged energy in a sinusoidal electromagnetic wave is:
A. overwhelmingly electrical.
B. slightly more electrical than magnetic.
C. equally divided between the electric and magnetic fields.
D. slightly more magnetic than electrical.
24. A vertical automobile radio antenna is sensitive to electric fields that are polarized:
A. horizontally.
B. in circles around the antenna.
C. vertically.
D. none of the above.
25. In a Newton's ring pattern, as one approaches the pattern's edge, the dark rings :
A. gets closer and thinner.
B. gets closer but remain of equal thickness .
C. are equally spaced but get thinner.
D. get farther apart and thinner.

26. Which of the following is true for Bragg's diffraction but not for diffraction from grating?
A. Two different wavelengths may be used.
B. For a given wavelength, a maximum may exist in several directions.
C. long waves deviated more than short ones.
D. Maxima occur only for particular angles of incidence.
27. In Compton scattering from stationary electrons the largest change in wavelength occurs when
the photon is scattered through:
A. 00.
B. 450.
C. 900.
D.1800.
28. A meson when at rest decays 2 microsec. after it is created. If moving in the laboratory at
0.99c (c-velocity of light), its lifetime according to laboratory clock would be:
A. the same.
B. 0.28 ms.
C. 14 microsec.
D. 4.6 s.
29. A console lamp in the cabin of a spaceship appears green when the ship and observer are both
at rest. When the ship is moving at 0.99c away from the Earth, passengers on board see :
A. a green lamp.
B. a violet lamp .
C. a red lamp.
D. nothing (The frequency is too high to be seen).
30. The significance of the square of the magnitude of the wavefunction of the particle is:
A. probability.
B. energy.
C. probability density.
D. energy density.
31. The reflection coefficient R for a certain barrier tunneling problem is 0.70. The corresponding
transmission coefficient T is:
A. 0.70.
B. 0.60.
C. 0.50.
D. 0.30.
32. If a wavefunction ѱ for a particle moving along the z-axis is normalized, then:
A. ʃ│ѱ│ dt = 1.
2

B. ʃ│ѱ│ dz = 1.
2

C. ∂ѱ/∂z = 1.
D. │ѱ│2 = 1.
33. The ground state energy of an electron in a one-dimensional potential well with zero potential
energy in the interior and infinite energy potential at the walls:
A. is zero.
B. decreases with temperature.
C. increases with temperature.
D. is independent of temperature.

34. The quantum number n is most closely associated with what property of the electron in a
hydrogen atom?
A. Energy.
B. Orbital angular momentum.
C. Spin angular momentum.
D. Magnetic moment.
35. The atom is in a state with orbital quantum number ℓ = 2. The number of possible values of
the magnetic quantum number mℓ is :
A. 2.
B. 3.
C. 4.
D. 5.
36. The Boolean expression (A + B)( A + B ) for the input logics A and B is equivalent to:
A. OR gate.
B. AND gate.
C. NOR gate.
D. XOR gate.
37. A photon with the smallest wavelength in the continuous x-ray is emitted when:
A. an electron is knocked from a K-shell.
B. the atom has the greatest recoil energy.
C. the incident electron loses all its energy in a single decelerating event.
D. a valence electron is knocked from the atom.
38. Which of the following group of particles follows Pauli exclusion principle?
A. photon , electron and neutron.
B. anti-neutrino, Z-boson and electron.
C. electron, neutron and proton.
D. phonon, proton and electron.
39. Electrons in a certain LASER make transitions from a metastable state to the ground state.
Initially there are 6 x 1020 atoms in the metastable state and 2 x 1020 atoms in the ground state.
The number of photons that can be produced in a single burst is about :
A. 2 x 1020.
B. 3 x 1020.
C. 4 x 1020.
D. 6 x 1020.
40. In a helium- neon LASER, The LASER light arises from a transition from a ------state to a ----
- state.
A. He, He.
B. Ne, Ne.
C. He, Ne.
D. Ne, He.
41. The Fermi energy of a metal depends mainly on:
A. the temperature.
B. the volume of the sample.
C. the strength of the applied magnetic field.
D. the number density of conduction electrons.
42. A hole refers to:
A. a positively charged electron.

B. an electron that has somehow lost its charge.
C. the absence of an electron in an otherwise filled band.
D. a microscopic defect in solid.
43. For a pure semiconductor the Fermi level is :
A. is in the conduction band.
B. well above the conduction band.
C. in the valence band.
D. near the center of the gap between the valence and conduction band.
44. Application of a forward bias to a p-n junction:
A. narrows the depletion zone.
B. increases the electric field in the depletion zone.
C. increases the potential difference across the depletion zone.
D. decreases the number of donors on the n-side.
45. Volumes of atomic nuclei are proportional to :
A. mass number (A).
B. A(A-1).
C. Atomic number(Z).
D. none of these.
46. The greatest binding energy per nucleon occurs for nuclides with masses near that of:
A. sodium.
B. iron.
C. mercury.
D. uranium.
47. When ordinary sulfur, 32S (Z=16), is bombarded with neutrons, the products are 32P (Z=15)
and:
A. an alpha particle.
B. a proton.
C. a deutron.
D. a gamma ray.
48. A nucleus with mass number A and atomic number Z undergoes electron capture. The mass
number and atomic number, respectively, of the daughter nucleus are :
A. A , Z-1.
B. A , Z+1.
C. A+1 , Z-1.
D. A-1 , Z+1.
49. The energies of electrons emitted in beta-decay have a continuous spectrum because:
A. the daughter nucleus may have any energy.
B. free electrons always have a continuous spectrum.
C. more than one electron is emitted in each decay.
D. the neutrino can carry off any energy up to a certain maximum.
50. The parity is NOT violated in the following nuclear transformation :
A. n → p + e-- + antineutrino.
B. p → n + e+ + neutrino ( inside nucleus).
C. p + e-- → n + neutrino ( electron capture).
D. n + p → 2H + gamma.
51. Which of the following particles is stable?

A. Neutron.
B. Proton.
C. Pion.
D. Muon.
52. An example of a fermion is:
A. photon.
B. pion.
C. neutron.
D. kaon.
53. All leptons interact with each other via the:
A. strong force.
B. electromagnetic force.
C. weak force.
D. strange force.
54. The DC signal can be converted to AC signal through the use of:
A. p-n diode.
B. astable multivibrator.
C. monostable multivibrator.
D. bistable multivibrator.
55. The attenuation coefficient of aluminium for soft X-rays is 1.73/cm. The fraction of X-rays
transmitted by 1.157cm thick aluminium sheet is :
A. 10%.
B. 13.5%.
C. 16.5%.
D. 19.5%.
56. The mass of proton is 1.67x10--27 kg and the charge 1.60x10--19 Coulomb. The frequency of
rotation of a proton in cyclotron whose magnetic field is 1.0T , is :
A. 45.3 MHz.
B. 35.3 MHz.
C. 25.3 MHz.
D. 15.3 MHz.
57. Which of the following particles has no magnetic moment associated with it?
A. Photon.
B. Proton.
C. Electron.
D. Neutron.
58. Deuteron and proton are moving with the same velocity in a medium. If the stopping power for
a proton is 2.0MeV/g-cm2, the stopping power of deuteron will be:
A. 2.0MeV/g-cm2.
B. 4.0MeV/g-cm2.
C. 6.0MeV/g-cm2.
D. 8.0MeV/g-cm2.
59. The gas multiplication factor of a GM counter increases if the:
A. potential difference is decreased and the radius of the anode wire increased.
B. only the potential difference is decreased.
C. the distance between the anode wire and the cathode is decreased.
D. the length of the anode wire is reduced.

60. Charged particles get accelerated in a cyclotron because of its motion:
A. inside dee in the presence of electric field.
B. inside dee in the presence of magnetic field.
C. outside dee in the presence of electric field.
D. outside dee in the presence of magnetic field only.
61. For the same sine wave, the ratio of the frequency of the output voltage of the half-wave
rectifier to the full wave rectifier is:
A. 0.5.
B. 1.0.
C. 1.5.
D. 2.5.
62. Impedance matching between two stages is generally accomplished through:
A. common base amplifier.
B. common emitter amplifier.
C. common collector amplifier.
D. none of the above.
63. The stability of the amplifier is increased by adding the portion of the output voltage to the
overall input voltage with the phase difference:
A. 00.
B. 900.
C. 1800.
D. 3600.

64. The modulation index of an AM wave is changed from 0 to1. The transmitted power is:
A. unchanged.
B. halved.
C. doubled.
D. increased by 50%.
65. The input current and the emitter current in the common emitter configuration are 0.79mA and
15.79mA , respectively. The voltage drop across the 1kOhm load is:
A. 0.79V.
B. 15.79V.
C. 15V.
D. 16.58V.
66. Reciprocal lattice of a body centered cubic lattice has :
A.1-fold rotational symmetry only.
B. 2-fold rotational symmetry.
C. 4-fold rotational symmetry.
D. 6-fold rotational symmetry.
67. The experimental evidence of the quantization of elastic waves in solids is provided by the:
A. photoelectric effect.
B. Compton effect.
C. Meissner effect.
D. lattice heat capacity.
68. Hall coefficient of a solid is:
A. increased by decreasing strength of the magnetic field.
B. increased by increasing strength of the magnetic field.
C. decreasing current through the sample.

D. unaffected by the change of above factors.
69. The number of energy states in a band is equal to the:
A. total number of electrons.
B. total number of atoms.
C. total number of primitive cells.
D. total number of unit cells.
70. Which of the following is not associated with the superconducting phase of solids?
A. Small mean free path of electrons.
B. Discontinuity in the heat capacity.
C. Josephson effect.
D. Meissner effect.
71. The hysteresis loop is associated with the:
A. diamagnetic substances.
B. paramagnetic substances.
C. para-electric substances.
D. ferroelectric substances.
72. The working substance in the process of adiabatic demagnetization:
A. is ferroelectric in nature.
B. is ferromagnetic nature.
C. is paramagnetic nature.
D. is diamagnetic nature.
73. In gamma ray transition:
A. atomic mass(A) may change.
B. atomic number(Z) may change.
C. atomic volume may change.
D. angular momentum of the states may or may not change.
74. Quarks are the constituents of:
A. all particles.
B. all leptons.
C. all strongly interacting particles.
D. only mesons.
75. Thermal neutrons:
A. raise the temperature of the substance when passing through it.
B. are essential for the fusion reactions.
C. has kinetic energy equivalent to free atoms at room temperature.
D. has more kinetic energy than that of fast neutrons.
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