51. A simple pendulum of length 1 has an energy E when its amplitude is A. If its amplitude is increased to 2 A, the energy becomes
a) E
b) E/2
c) 2E
d) 4E
Ans: d
52. If the kinetic energy and potential energy of a simple harmonic oscillator of amplitude A are both equal to half the total energy, then the displacement is equal to
a) A
b) A/2
c) A/V2
d) AV2
Ans: c
53. The ratio of kinetic energy and potential energy of a simple harmonic oscillator, at a displacement equal to half its amplitude is given by
a) 1:2
b) 1:1
c) 2:1
d) 3:1
Ans: d
54. A simple pendulum of length / has an energy E, when its amplitude is A. If the length of pendulum is doubled, the energy will be
a) E
b) E/2
c) 2E
d) 4E
Ans: b
55. Time period and length of a seconds pendulum respectively are
a) 1 sec and 99.4 cm
b) 1 sec and 92.7 cm
c) 2 sec and 99.4 cm
d) 2 sec and 92.7 cm
Ans: c
56. One end of an elastic string of natural length / and modulus X is kept fixed while to the other end is attached a particle of mass m which is hanging freely under gravity. The particle is pulled down vertically through a distance x, held at rest and then released. The motion is
a) a simple harmonic motion
b) a rectilinear motion with constant speed
c) a damped oscillatory motion
d) none of the above
Ans: a
57. A particle is executing simple harmonic motion in a line 1.0 m long. If the time of one complete vibration is 1 sec, then the maximum velocity of the particle is
a) 1.00 m/sec
b) 1.57 m/sec
c) 3.14 m/sec
d) 6.28 m/sec
Ans: c
58. The potential energy of a particle falling through a straight shaft drilled through the earth (assumed homogenous and spherical) is proportional to
a) log r
b) r
c) r2
d) 1/r
where r is the distance of’the particle from centre of the earth
Ans: c
59. Joule is the unit of
a) power
b) impulse
c) work
d) momentum
Ans: c
60. One Newton is equivalent to
a) 105 dyne
b) 106 dyne.
c) 107 dyne
d) 981 dyne
Ans: a
61. A quantity whose dimensions are M2L2 T3 could be the product of
a) force and pressure
b) mass and power
c) energy and velocity
d) force and velocity
Ans: b
62. The dimensions of Gravitational Universal constant ‘G’ are
a) M-‘L2r2
b) M-‘L3r2
c) M-2L3T2
d) M’L3T2
Ans: b
63. Williot-Mohr diagram is used to determine deflection in
a) trusses only
b) beam only
c) rigid frames only
d) any type of structure
Ans: a
64. One Joule is equivalent to
a) 9.81 Newton – metre
b) 1 Newton – metre
c) 1 kg wt – metre
d) 1 dyne – metre
Ans: b
65. The dimensions of centrifugal force are
a) M1 L2 T2
b) M’L’T1
c) M’L’T2
d) M’L-‘T2
Ans: c
66. A quantity measured in the C.G.S system of units has dimensions M”2L3 T3/2. What numerical factor would be required to convert the quantity to SI units ?
a) 1
b) 100
c) 1/100
d) 1/10000
Ans: a
67. The unit of rotational inertia of a body in C.G.S system is
a) cm4
b) kg-cm2
c) gm-cm2
d) gm-cm3
Ans: c
68. The ratio of unit of force in gravitational system to that in absolute system is
a) 1
b) g
c) 1/g
d) none of the above
where ‘g’ is acceleration due to gravity
Ans: b
69. In SI units, the units of force and energy are respectively
a) Newton and watt
b) Dyne and erg
c) Newton and joule
d) kg-wt and joule
Ans: c
70. The dimensions of power are.
a) M’L2T2
b) M’L’T3
c) M’L’r2
d) M’L-‘T*
Ans: b
71. Impulse can be obtained from a
a) force-displacement diagram
b) force-time diagram
c) velocity-time diagram
d) velocity-displacement diagram
Ans: b
72. One Newton is equivalent to
a) 1 kg-wt
b) 9.81 kg-wt
c) 981 dyne
d) 1/9.81 kg-wt
Ans: d
73. Which of the following is a scalar quantity?
a) energy
b) momentum
c) torque
d) impulse
Ans: a
74. A heavy ladder resting on floor and against a vertical wall may not be in equilibrium if
a) floor is smooth and wall is rough
b) floor is rough and wall is rough
c) both floor and wall are rough
d) both floor and wall are smooth
Ans: d
75. Coefficient of friction depends on
a) nature of surfaces only
b) area of contact only
c) both (a) and (b)
d) none of the above
Ans: a