61. The potential energy of particle executing Simple Harmonic Motion (S.H.M.) with amplitude ‘A’ is maximum when displacement is
(A) Zero (B) +
(C) + (D) + A
Ans. (D)
62. Which waves are used in sonography?
(A) Sound Waves (B) Micro waves
(C) Infrared waves (D) none of these
Ans. (D)
63. Unit of Stefan‘s constant is
(A) Watt/m2 K4 (B) Watt/m2 K
(C) Watt – m2 K4 (D) Watt – m2 / K4
Ans. (A)
64. A semiconductor has an electron concentration of 8 x 1013 per m3 and hole concentration of 5.5 x 1012 m3. The semiconductor is
(A) n – type (B) p – type
(C) intrinsic semiconductor (D) p-n junction
Ans. (A)
65. A current carrying loop is placed in a uniform magnetic field. The torque acting on its does not depend on
(A) Shape of the loop
(B) Area of the loop
(C) Number of turns in the loop
(D) Strength of the magnetic field
Ans. (A)
66. Minimum energy required to take out the only one electron from ground state of He+ is
(A) 6.8 eV (B) 13.6 eV
(C) 27.2 eV (D) 54.8 eV
Ans. (D)
67. To get three images of a single object, one should have two plane mirrors an angle of
(A) 300 (B) 600
(C) 900 (D) 1200
Ans. (C)
68. According to Curie’s law, the magnetic susceptibility of a substance at absolute temperature T is proportional to
(A) (B)
(C) T (D) T2
Ans. (A)
69. An electric dipole placed in a non-uniform electric field experiences
(A) Both, a torque and a net force
(B) Only a force but no torque
(C) Only a torque but no net force
(D) No torque and no net force
Ans. (A)
70. The angle between electric dipole moment and the electric field strength due to it on the axial line is
(A) 00 (B) 450
(C) 900 (D) 1800
Ans. (A)
71. E.M.F. of cell depends upon
(A) Internal resistance
(B) External resistance
(C) Electrolyte and the electrodes of the cell
(D) None of these
Ans. (C)
72. If the electric current in a lamp decreases by 5%, then the power output decreases by
(A) 5% (B) 10%
(C) 20% (D) 40%
Ans. (B)
73. The cyclotron frequency of an electron gyrating in a magnetic field of one Tesla is
(A) 28 GHz (B) 56 GHz
(C) 84 GHz (D) 112 GHz
Ans. (A)
74. Susceptibility is positive but smaller for
(A) Ferromagnetics (B) Diamagnetics
(C) Paramagnetics (D) Non-magnetic substance
Ans. (C)
75. Self-inductance of a straight conductor is
(A) Zero (B) Infinity
(C) Very large (D) Very small
Ans. (A)
76. The idea of displacement was given by
(A) Max Planck (B) Huygen
(C) Hertz (D) Maxwell
Ans. (D)
77. A 600 prism has refractive index . What is the angle of minimum deviation?
(A) 300 (B) 600
(C) 900 (D) 1800
Ans. (A)
78. The ratio of the specific charge of a proton to that of an α particle is
(A) 1:1 (B) 2:1
(C) 1:3 (D) 4:1
Ans. (B)
79. Which of the following particle is unstable?
(A) Proton (B) Neutron
(C) Electron (D) Alpha particle
Ans. (B)
80. The process of superimposing signal frequency on a carrier wave is
(A) Transmission (B) Reception
(C) Modulation (D) Detection
Ans. (C)
