Physics Objective type question bank -3

If a body is rotating about an axis, passing through its centre of mass then its angular momentum is directed along its (MNR 77, NCERT 82, PMT MP 86)
(a) Radius (b) Tangent
(c) Circumference (d) Axis of rotation
Answer: (d)


If a horizontal cylindrical tube, partly filled with water is rapidly rotated about a vertical axis passing through its centre, the moment of inertia of the water about its axis will
(a) Decrease
(b) Increase
(c) Not change
(d) Increase or decrease depending upon clock wise or anticlockwise sense of rotation
Answer: (b)
A sphere of mass 0.5 kg and diameter 1 m rolls without sliding with a constant velocity of5 m/s. what is the ratio of the rotational K.E. to the total kinetic energy of the sphere? (MHT-CET-2002)
(a) (b)
(c) (d)
Answer: (c)
represents (MHT-CET-2003)
(a) Rotational kinetic energy of a particle
(b) Potential energy of a particle
(c) Torque on a particle
(d) Power
Answer: (a)
The total energy of rolling ring of mass ‘m’ and radius ‘R’ (MHT-CET-2007)
(a) 3/2 mv2 (b) 1/2 mv2
(c) mv2 (d) 5/2 mv2
Answer: (c)

When a steady torque is acting on a body, the body (NCERT 73)
(a) Continues in its state of rest or uniform motion along a straight line
(b) Gets linear acceleration
(c) Gets angular acceleration
(d) Rotates at a constant speed
Answer: (d)
The M.I. of a solid cylinder of mass M and radius R about a line parallel to the axis of the cylinder and ling on the surface of the cylinder is (MP-PMT 94)
(a) (b)
(c) (d)
Answer: (c)
The moment of inertia of a body comes into play
(AFMC (pune) 79)
(a) In motion along a curved path
(b) In linear motion
(c) In rotational motion
(d) None of the above
Answer: (c)
The speed of a homogeneous, solid sphere after rolling down in the inclined plane of vertical height h, from rest without sliding is (CBSE 92)
(a) (b)
(c) (d)
Answer: (a)
Two disc with same mass but different radii are moving with same K.E. one of them rolls and other slides without friction. Then [MH-CET 2000]
(a) Rolling disc has greater velocity
(b) Sliding disc has greater velocity
(c) Both have same velocity
(d) The disc with greater radius will have greater velocity.
Answer: (b)