MCQ
61. The angle between two forces when the resultant is maximum and minimum respectively are-
0° and 180°
180° and 0°
90°
90° and 0°
62. The rate of charge of displacement of a body is called.
Velocity
acceleration
momentum
none
63. Kinetic friction is the-
tangent of angle between normal reaction and the resultant of normal reaction and the limiting friction
ratio of limiting friction and normal reaction
the friction force acting when the body is just about to move
the friction force acting when the body is in motion
64. The maximum frictional force which comes into play when a body just begins to slide over another surface is called-
limiting friction
sliding friction
rolling friction
kinematic friction
65. In detennining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than-
two members with unknown forces of the frame
three members with unknown forces of the frame
four members with unknown forces of the frame
three members with known forces of the frame
66. The total motion possessed by a body is called-
impulsive force
mass
wight
momentum
67. Concurrent forces are those forces whose lines of action-
lie on theme line
meet at one point
meet on the same plane
none of these
68. Tangent of angle of friction is equal to-
kinetic friction
limiting friction
angle of repose
coefficient of friction
69. The algebraic sum of moments of the forces. forming couple about any point in their plane is-
equal to the moment of the couple
constant
both of above are correct
both of above are wrong
70. A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span-
এখানে,
w=1.2kg
I = 20m
T = 1500kg
আমরা জানি, T = wI²/8x
⇒ x = wI²/8T
= 1.2×20²/8x1500
=0.04m = 4cm
2.5cm
3.0cm
4.0cm
5.0cm
71. Two coplanar couples having equal and opposite moments-
balance each other
produce a couple and an unbalanced force
are equivalent
can not balance each other
72. force while acting on a body may-
change its motion
balance the forces already acting on it
give rise to the internal stresses in it
all of those
73. The co-efficient of friction depends upon-
nature of surfaces
area of contact
shape of the surfaces
all of the above
74. When trying to turn a key into a lock, following is applied-
coplanar force
non-coplanar forces
lever
couple
75. Limiting force of friction is the-
tangent of angle between normal reaction and the resultant of normal reaction and limiting friction
ratio of limiting friction and normal reaction
the friction force acting when the body is just about to move
the friction force acting when the body is in motion
76. Which of the following do not have identical dimensions?
Momentum and impulse
Torque and energy
Torque and work
Moment of a force and angular momentum
77. The product of either force of couple with the arm of the couple is called-
resultant couple
moment of the forces
resulting couple
moment of the couple
78. In order to determine the effects of a fore, acting on a body we must know-
magnitude of the force
line of action of the force
nature of the force i, e whether the force is push or pull
all of these
79. Dynamic friction as compared to static friction is-
same
more
less
maybe less of more depending on nature of surfaces and velocity
80. Coulomb friction is the friction between-
bodies having relative motion
two dry surfaces
two lubricated surfaces
solids and liquids