# Rotational Motion

### A particle performing uniform circular motion has angular momentum

A particle performing uniform circular motion has angular momentum L. If its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is

1. L/4
2. 4L
3. L/2
4. 2L

### Moment of inertia of a circular wire of mass M and radius R

Moment of inertia of a circular wire of mass M and radius R about its diameter is

1. (MR2)/2
2. MR2
3. (MR2)/4
4. 2MR2

### A thin uniform rod of length l and mass m is swinging

A thin uniform rod of length l and mass m is swinging freely about a horizontal axis passing through its end. Its maximum angular speed is ω. Its centre of mass rises to a maximum height of

1. ωl/(6g)
2. ω2l2/(2g)
3. ω2l2/(6g)
4. ω2l2/(3g)

### A mass ‘m’ is supported by a massless string wound around a uniform

A mass ‘m’ is supported by a massless string wound around a uniform hollow cylinder of mass m and radius R. If the string does not slip on the cylinder, with what acceleration will the mass fall on release?

1. g
2. 5g/6
3. g/2
4. 2g/3

### A uniform solid cylindrical roller of mass m is being pulled on a horizontal surface with force

A uniform solid cylindrical roller of mass m is being pulled on a horizontal surface with force F parallel to the surface and applied at its centre. If the acceleration of the cylinder is a and it is rolling without slipping then the value of F is:

1. ma
2. 2 ma
3. 3/2 ma
4. 5/3 ma