PU CET PG 2019 Question Paper MSc_HS__Physics OR Medical Physics OR Physics _ Electronics_

MSc(HS)(Physics/Medical Physics/Physics & Electronics)
1. In the Michelson interferometer, the compensating plate is used for
A) Inducing symmetry in the optical elements.
B) Compensating the extra path traversed by reflected waves after splitting of beam.
C) Getting circular shape of interference fringes.
D) Replacing bright central fringe with dark one.

2. The output of the Nicol prism, when monochromatic natural light is incident on it, is
A) Ordinary ray with vibrations perpendicular to optic axis of crystal.
B) Extraordinary ray with vibrations parallel to optic axis of crystal
C) Extraordinary ray with vibrations perpendicular to optic axis of crystal.
D) Ordinary ray with vibrations parallel to optic axis of crystal.

3. The role of Helium atoms in the He-Ne laser is to
A) Help in excitation and population inversion of Neon atoms.
B) Help in maintaining optical resonance.
C) Result in the emission of red colour light.
D) Absorb the light of colours other than red.

4. A thick sheet of glass 3.7µm is placed in the path of one of the interfering beams, of the
wavelength 550nm, in the Fresnel biprism arrangement. If the central maximum is shifted
to the position earlier occupied by the 5th bright fringe, the refractive index of the sheet is
A) 1.65 B) 1.54 C) 1.74 D) 1.43

5. Calculate the radius of 3rd half period zone of the zone plate of focal length 1.5m
illuminated by light of wavelength 593nm
A) 2.04mm B) 1.98mm C) 1.07mm D) 1.63mm

6. A parallel beam of monochromatic light of wavelength 500nm is incident normally on a
plane diffraction grating having 4000 lines per centimetre. The angle of diffraction for first
order principal maxima is given by
A) Sinθ = 0.5 B) Sinθ = 0.7 C) Sinθ = 0.2 D) Sinθ = 0.1

7. The interference differs from the diffraction in that
A) It can be observed with white light
B) Unlike diffraction the interference fringes are of varying intensity
C) Interference minima are perfectly dark but that of that of diffraction are not so
D) The diffraction fringes are of equal width but interference fringes are of unequal width

8. Which of the following is not an experimental technique to obtain a polarised beam of light
A) Dichorism B) Reflection from a clear liquid surface
C) Interference by division of wave front D) Double refraction

9. A ray of light strikes a glass plate at an angle of 60o. If the reflected and refracted light
are perpendicular to each other, the refractive index of the glass is
A) 1.33 B) 2.14 C) 1.97 D) 1.73

10. Which of the following is not a characteristic of a under-damped oscillating systems :
A) Frequency of oscillations is lower than that for free oscillator
B) Amplitude of oscillations decreases with each oscillation
C) Energy of the oscillating systemis conserved throughout the oscillation
D) Dissipative forces are smaller than the restoring forces

11. Calculate the maximum current in the RC harmonic oscillator consisting of inductance of
0.2mH and capacitance of 5.12µF, when maximum voltage across the capacitor is 0.1V.
A) 16mA B) 8mA C) 4mA D) 10mA

12. The forced series LCR electrical oscillator is not characterised by which of the following
properties
A) At resonance, the inductive and capacitive reactance counterbalance each other.
B) The current is maximum at resonance.
C) The power absorption from source is minimum at resonance.
D) Oscillation frequency solely depends upon inductance and capacitance at resonance.

13. When electromagnetic wave propagates through a dielectric medium, then
A) Electric and magnetic fields oscillate in phase and with same frequency.
B) Electric and magnetic fields oscillate in phase but not with same frequency.Magnetic
C) Field oscillates with a phase lag relative to electric field.
D) Electric field oscillates with a phase lag relative to magnetic field.

14. The relative permittivity of the medium is 3.24. The refractive index of this medium will be:
A) 2.2 B) 1.8 C) 1.6 D) 2.0

15. The Poynting vector associated with an electromagnetic wave informs about:
A) Power flux and direction of propagation of EM wave.
B) Frequency of EM wave.
C) Rate of oscillations of electric and magnetic field intensities.
D) Dispersive power of the medium through which EM wave is propagating.

16. The electric field intensity (in SI units) inside a charged spherical shell of radius 15m and
surface charge density 15µC per m2 is
A) 1 B) 1/15 C) 0 D) 15

17. The electric lines of force at any point on the equipotential surfaces
A) Are parallel to it B) Are inclined at acute angles.
C) Are normal to it D) Are inclined at obtuse angles

18. A current of 10A flows through a conductor of cross-section 1mm2. If the density of charge
carriers is 1021cm-3, then the drift velocity of electrons is

A) 6.25cm/s B) 6.25mm/s C) 62.5m/s D) 0.625mm/s

19. The resistivity of conductor increases with temperature because of
A) Decrease of relaxation time B) Increase in relaxation time
C) Increase in mean free path of electrons D) Increase in charge carrier density.

20. The magnetic field intensity due to a long current carrying solenoid is proportional to
A) Inversely proportional to current
B) Directly proportional to number of turns of wire
C) Independent of permeability of core introduced
D) Inverse proportional to permeability of core

21. Which of the following processes makes use of electromagnetic induction
A) Charging a storage battery.
B) Magnetising an iron piece with a bar magnet.
C) Generation of hydroelectricity.
D) Magnetising a soft iron piece by placing inside a current carrying solenoid.

22. The ratio E(axial)/E(Equatorial) between axial and equatorial electric fields due to a short
electric dipole is
A) 1.5 B) 2.0 C) 1.0 D) 0.5

23. Two streams of electrons moving parallel to each other in the same direction
A) Attract each other B) Repel each other
C) Cancel the electric field of each other D) Cancel the magnetic field of each other

24. The ferromagnetic materials are characterized by
A) Negative value of susceptibility
B) Small but positive value of susceptibility
C) Large positive value of susceptibility
D) Zero value of susceptibility

25. An electric dipole is place in uniform electric field, it is acted upon by:
A) A force and a torque B) Neither a force nor a torque
C) A torque only D) A force only

26. A bar magnet is cut into two equal pieces. The pole strength of either piece will be
A) Halved B) Unchanged C) Doubled D) Reduced to zero

27. Ferrites are the materials, which are not characterized by
A) Negative electrical conductivity
B) Rectangular shaped hysteresis loop
C) High Joule’s heating on current flow
D) Two sub-lattices with unequal and opposite magnetic moments

28. To shield an instrument from the external magnetic field, it may be placed in the cabinet
made of
A) Wood B) Ebonite C) Metal D) Diamagnetic substance

29. In a region where electric field is 5N/C, 40 lines of electric force are crossing per m2. The
number of lines crossing per m2, where the electric field intensity is 10N/C will be;
A) 20 B) 80 C) 100 D) 200

30. The length of the meter stick moving parallel to its length, when its mass is 1.5 times its
rest mass, is
A) 150cm B) 66.7 cm C) 75cm D) 125cm.

31. The planets revolving around the sun in the solar system obey the law, relating their time
period of revolution and average radius of orbit, which can be expressed as:
A) T ∝ r B) T ∝ r C) T ∝ r D) T ∝ r
3 2 3 2 5

32. The aircraft at take off stage is an example of
A) Inertial reference frame B) Non-inertial reference frame
C) Universal reference frame D) Stationary frame

33. The radius of carbon atom in the diamond crystal structure having cubic unit cell edge
16 3 nm is
A) 6nm B) 8nm C) 16 3 nm D) 8 3 nm

34. The continuous component x-ray spectrum owes its origin to
A) Photoelectric effect B) Bremmstrahlung.
C) Pair production D) Compton effect

35. The well-defined wave function must not be
A) Single valued B) Continuous w.r.t space coordinates
C) Obey the principle of superposition D) Always areal function

36. The moving particle confined in an infinite potential well is not characterised by which of
the following:
A) Quantized negative energy states
B) Ground state is not the state of rest
C) Quantized wave functions defining different probability distribution for the particle
D) Quantized positive energy states

37. Which of the following energy terms does not contribute in the binding energy formula
derived using liquid drop model for nucleus:
A) Surface energy B) Asymmetry energy
C) Heisenberg Exchange energy D) Coulomb’s energy.

38. For the alpha decay from natural radionuclides, which of the following observations does
not hold true:
A) The emission of alpha particle takes place following tunnelling of barrier.
B) The energetic alpha particles are emitted by radionuclide with shorter half life.
C) The energy required by alpha particle to penetrate a radionuclide is much smaller than
the kinetic energy of alpha particle emitted by that radionuclide.
D) The alpha decaying radionuclides have mass number greater than 200.

39. Which of the following properties is not associated with the neutrino particle
A) Nearly zero mass B) No charge C) Integral spin D) Spin=1/2.

40. A radioactive specimen, consisting of 10000 active atoms, has a half life of 1 hour. How
many radioactive atoms will be left in the specimen after a duration of 3hours
A) 1250 B) 5000 C) 2500 D) 7500

41. Quadrupole moment of a doubly magic nucleus is always
A) Positive but small B) Negative but large
C) Zero D) Positive and large

42. The radius of 8Be4 nucleus is 2.4fm. The radius of 27Al13 nucleus will be:
A) 4.8fm B) 3.6fm C) 3.0 fm D) 4.2fm

43. The kinetic energy of each of the electron and positron generated in the pair production
of photon having energy of 1.522MeV will be
A) 756KeV B) 250KeV C) 400KeV D) 150KeV

44. A photon of 45 pico-meter wavelength undergoes scattering by loosely bound electron
nearly at rest. The maximum wavelength of the scattered photon will be
A) 45.0 pico-meter B) 47.4 pico-meter C) 49.8 pico-meter D) 48.2 pico-meter

45. The photoelectric emission of K-shell electron, with binding energy of 3.2eV, is caused
by a 6.5keV photon. The kinetic energy of emitted electron is:
A) 9.7keV B) 4.9keV C) 3.3keV D) 3.2keV.

46. The atomic packing fraction of face-centred cubic is
π π π 2 3π
A) B) C) D)
3 2 2 3 2
47. Number of atoms per unit cell in case of body-centred cubic is
A) 2 B) 1 C) 3 D) 4

48. For the Van der waal’s force, the dependence of the interaction energy on distance r is
proportional to
A) ~ r-6 B) ~ r-7 C) ~ r-3 D) ~ r2

49. A 214Pb (Z = 82) nucleus decays via two β - decays and one alpha decay, the resulting
nucleus is

A) 210Pb B) 210Bi C) 210Au D) 210Pt

50. Miller indices of the plane parallel to the x-axis and y-axis are
A) (0,0,1) B) (1,0,0) C) (0,1,0) D) (1,1,0)

51. In case of a system of identical, indistinguishable particles obeying Pauli exclusion
principle, the number of particles in each energy state ε at the temperature T is
proportional to (k is Boltzmann constant and εf is the Fermi energy)
1 1
A) B)
exp[(ε − ε f ) / kT ] + 1 exp[(ε − ε f ) / kT ] − 1
1 1
C) D)
1 − exp[(ε − ε f ) / kT ] exp[ε / kT ] + 1

52. In an p-type Silicon, which of the following statements is true:
A) Electrons are majority carriers and pentavalent atoms are the dopants
B) Electrons are minority carriers and pentavalent atoms are dopants.
C) Electrons are minority carriers and trivalent atoms are the dopants
D) Electrons are majority carriers and trivalent atoms are the dopants

53. In full wave rectifier with input frequency of 50 Hz, the frequency of the output is
A) 50 Hz B) 100 Hz C) 150 Hz D) 200 Hz

54. For a transistor amplifier, the voltage gain
A) Remains constant for all frequencies
B) Is high at high and low frequencies and constant in middle frequencies
C) Is low at high and low frequencies andconstant middle frequencies
D) Is continuously decreasing with frequency

55. In case of the transistor connected in the common emitter configuration, the
input resistance is defined as ratio of
A) Change in VCE and to change in VBE, with IB kept constant.
B) Change in VCE and to change in IC, with IBkept constant.
C) Change in VBE and to change in VCE, IB with kept constant.
D) Change in IB and to change in VBE, with VCE kept constant.

56. Two amplifiers are connected one after the other in series. The first amplifier
has a voltage gain of A1 and the second has a voltage gain of A2. The overall gain
of the combination will be
A) A1A2 B) A1 + A2 C) A1 -A2 D) A1/A2

57. The least preferred principal crystal structures for themetallic crystals is:
A) Simple cubic B) Body centred cubic

C) Face centred cubic D) Hexagonal

58. The base of an npn transistor is
A) Heavily doped B) Lightly doped
C) Metallic D) Doped by pentavalent material

59. A reverse voltage of 10 V is applied across a Si diode. The magnitude of voltage across
the depletion layer will be
A) 0 V B) ~ 0.7 V C) ~ 10 V D) ~ 1.1 V

60. The thermally generated electrons and holes acquire sufficient energy from the applied
potential to produce new carriers by removing valence electrons from their bonds. These
new carriers in turn produce additional carriers again through the process of disrupting
bonds. The cumulative process is referred to as
A) Avalanche breakdown B) Zener breakdown
C) Avalanche multiplication D) Zener multiplication

61. The basic Collpitts oscillator uses
A) Two inductor and one capacitors B) One inductor and two capacitors
C) Two capacitors D) Tickler coil

62. The light emitted diodes consist of
A) GaAs B) GaInP C) GaAlInP D) InAs

63. VLSI circuits are integrated circuits having
A) More than 10 gates B) More than 1000 gates
C) More than 100 gates D) No gate

64. The possible values of the total angular momentum quantum number J under LS coupling
of two atomic electrons whose orbital quantum numbers are l1 = 1 and l2 = 2 are
A) 1,2,3 B) 0,1,2,3,4 C) 0,1,2,3 D) 2,3,4
65. The barn unit of cross section is equal to
A) 100 fm2 B) 10-28 fm2 C) 10-24 fm2 D) 10-15 m2
66. A force F = ( 4iˆ − 2 ˆj + 3kˆ ) N is applied at the point B (5,-1,3) of a body which rotates
about an axis through the point A (1,2,-1). Position coordinates are expressed in meters.
Then the torque acting on the body is
A) ( −iˆ − 4 ˆj + 4 kˆ ) N m B) ( −iˆ + 4 ˆj − 4kˆ ) N m
C) ( −iˆ + 4 ˆj + 4 kˆ ) N m D) (iˆ + 4 ˆj + 4 kˆ ) N m

67. A body of mass 1 kg having velocity v1 = (5iˆ − 4 ˆj + 3kˆ ) m/s at r1 = = ( 4iˆ + 6 ˆj − 2 kˆ ) m is
moved to position r2 = (5iˆ + 8 ˆj + kˆ ) m along a straight line by force F = ( 2iˆ − 3 ˆj + 4 kˆ ) N.
The work done in moving the particle is
A) 8 J B) 12 J C) 16 J D) 9 J

( )
68. An alternating current is given by 3 sin ωt + cos ωt . The root mean square value of the
current is
A) 2 ( )
B) 3 sin ωt + cos ωt C) 2 D) 4
69. A particle is limited to the x-axis has the wave function ψ = a x between x = 0 and x =1;
and ψ = 0 elsewhere. The expectation value of the particle position is
A) a B) a2/3 C) 3/4 D) a3/4
70. The value of divergence of curl of vector A is
A) Gradient of A B) Laplacian of A C) 0 D) Infinity
71. Four level lasers are preferred because their
A) Population inversion can be achieved only under intense pumping conditions
B) Wavelength of output laser is always low
C) Population inversion can be easily achieved and also sustained
D) None of these

72. The relationship between energy (E) and momentum (p) of a massless particle is
A) E = pc2 B) E=p/c C) E= pc D) E=mc2
73. The average energy of a molecule of HCl gas exhibiting translation, rotation and
vibration motion is (k is Boltzmann constant and T is absolute temperature)
A) 3/2 kT B) 5/2 kT C) 7/2 kT D) 9/2 kT
74. In which of the following heat loss is primarily not due to convection
A) Boiling of water
B) Land and sea breeze
C) Heating of glass surface of a bulb due to current in filament
D) Circulation of air around blast furnace
75. In the adiabatic expansion of gas
A) Pressure increases B) Temperature falls
C) Density increases D) Thermal energy increases
x-x-x