Rotational Motion JEE Main

I want the sample questions of Rotational Motion chapter of Physics for preparation of Joint Entrance exam JEE Main exam?

[shikha]

Ok, here I am providing you the sample questions of Rotational Motion chapter for Joint Entrance exam JEE Main exam.

JEE Main exam Rotational Motion questions

Moment of inertia of a disc about an axis which is tangent and parallel to its plane is I. then the moment of inertia of disc about a tangent,, but perpendicular to its plane will be

(a) 3I/4 (b) 3I/3

(c) 5I/6 (d) 6I/5

Calculate the M.I. of a thin uniform ring about an axis tangent to the ring and in a plane of the ring, if its M.I. about an axis passing through the centre and perpendicular to plane is 4 kg m2.

(a) 12 kg m2 (b) 3 kg m2

(c) 6 kg m2 (d) 9 kg m2

Answer: (c)

By keeping moment of inertia of a body constant, if we double the time period, then angular momentum of body (MHT-CET-2005)

(a) Remains constant (b) Becomes half

(c) Doubles (d) Quadruples

Answer: (b)

The torque acting is 2000Nm with an angular acceleration of 2 rad/s2. the moment of inertia of body is (MHT-CET-2004)

(a) 1200 kgm2 (b) 900 kgm2

(c) 1000 kgm2 (d) Can’t say

Answer: (d)

For increasing the angular velocity of a object by 10%, the kinetic energy has to be increased by

(a) 40% (b) 20%

(c) 10% (d) 21%

Answer: (d)

A body of M.I. of 5 kg m2, rotating with an angular velocity of 6 rad/s, has the same kinetic energy as a mass of 20 kg, moving with a velocity of

(a) 3 m/s (b) 2 m/s

(c) 4 m/s (d) 5 m/s

Answer: (a)

A particle of mass m is moving with a constant velocity along a line parallel to the +ve direction of the X-axis. The magnitude of its angular momentum w.r.t the origin

(a) Is zero

(b) Goes on increasing as x is increased

(c) Goes on decreasing as x is increased

(d) Remains constant for all positions of the particle

Answer: (d)

A dancer on ice spins faster when she folds here arms. This is due to (CPMT. PMT MP 86)

(a) Increases in energy and increase in angular momentum

(b) Decrease in friction at the skates

(c) Constant angular momentum and increase in kinetic energy

(d) Increase in energy an decreases in angular momentum

Answer: (c)

A mass is revolving in a circle which is in the plane of the paper. The direction of angular acceleration is

(a) Upward to the radius

(b) Towards the radius

(c) Tangential

(d) At right angle to angular velocity

Answer: (c)

Angular momentum is (CBSE 93)

(a) A scalar

(b) A polar vector

(c) A scalar as well as vector

(d) An axial vector

Answer: (d)

Which is the wrong relation from the following?

(a) t = I a (b) F = ma

(c) L = I w (d) I = t a

Answer: (d)