Q. No.Let IA and IB be moments of inertia of a body about two axes A and B respectively. The axis A passes through the centre of mass of the body but B does not.
1. IA < IB
2. If IA < IB, the axes are parallel
3. If the axes are parallel, IA < IB
4. If the axes are not parallel, IA ≥ IB
A sphere is rotating about a diameter,
| 1. | the particles on the surface of the sphere do not have any linear acceleration. |
| 2. | the particles in the diameter mentioned above do not have any linear acceleration. |
| 3. | different particles on the surface have different angular speeds. |
| 4. | all the particles on the surface have the same linear speed. |
The density of a rod gradually decreases from one end to the other. It is pivoted at an end so that it can move about a vertical axis through the pivot. A horizontal force F is applied on the free end in a direction perpendicular to the rod. The quantities, that do not depend on which end of the rod is pivoted, are
1. angular acceleration
2. angular velocity when the rod completes one rotation
3. angular momentum when the rod completes one rotation
4. torque of the applied force
If there is no external force acting on a non-rigid body which of the following quantities must remain constant?
| a. | angular momentum |
| b. | linear momentum |
| c. | kinetic energy |
| d. | moment of inertia |
| 1. | (a) and (b) |
| 2. | (b) and (c) |
| 3. | (c) and (d) |
| 4. | (a) and (d) |
A particle moves on a straight line with a uniform velocity. Its angular momentum:
| a. | is always zero. |
| b. | is zero about a point on the straight line. |
| c. | is not zero about a point away from the straight line. |
| d. | about any given point remains constant. |
Choose the correct option:
| 1. | (a), (b) and (c) |
| 2. | (a), (b) and (d) |
| 3. | (b), (c) and (d) |
| 4. | none of these |
Consider the following two equations
(A) L = I ω (B) \(\frac{dL}{dt}=\Gamma\)
In noninertial frames:
1. both A and B are true
2. A is true but B is false
3. B is true but A is false
4. both A and B are false
The axis of rotation of a purely rotating body:
| a. | must pass through the centre of mass |
| b. | may pass through the centre of mass |
| c. | must pass through a particle of the body |
| d. | may pass through a particle of the body |
Choose the correct option:
| 1. | (a) and (b) |
| 2. | (b) and (d) |
| 3. | (a) and (c) |
| 4. | (a), (b) and (d) |
A person sitting firmly over a rotating stool has his arms stretched. If he folds his arms, his angular momentum about the axis of rotation:
| 1. | increases | 2. | decreases |
| 3. | remains unchanged | 4. | doubles |
A thin circular ring of mass \(M\) and radius \(r\) is rotating about its axis with an angular speed \(\omega\). Two particles having mass \(m\) each are now attached at diametrically opposite points. The angular speed of the ring will become:
1. \(\frac{\omega M}{M+m}\)
2. \(\frac{\omega M}{M+2 m}\)
3. \(\frac{\omega(M-2 m)}{M+2 m}\)
4. \(\frac{\omega(M+2 m)}{M}\)
A cubical block of mass M and edge a slides down a rough inclined plane of inclination θ with a uniform velocity. The torque of the normal force on the block about its centre has a magnitude
1. zero
2. Mga
3. Mga sin θ
4. \(\frac{1}{2}\) Mga sin θ
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