A solid sphere is rotating freely about its symmetry axis in free space. The radius of the sphere is increased keeping its mass same. Which of the following physical quantities would remain constant for the sphere?

1. Angular velocity 

2. Moment of inertia

3. Angular momentum 

4. Rotational kinetic energy

The bricks, each of length L and mass M, are arranged as shown from the wall. The distance of the centre of mass of the system from the wall is :

(1) L/4

(2) L/2

(3) (3/2) L

(4) (11/12) L

A uniform disk of mass M and radius R is mounted on a fixed horizontal axis. A block of mass m hangs from a massless string that is wrapped around the rim of the disk. The magnitude of the acceleration of the falling block (m) is :

(1) $\frac{2M}{M+2m}g$

(2) $\frac{2m}{M+2m}g$

(3) $\frac{M+2m}{2M}g$

(4) $\frac{2M+m}{2M}g$

A horizontal force F is applied such that the block remains stationary. Then which of the following statement is false?

(1) f = mg [where f is the friction force]

(2) F = N [where N is the normal force]

(3) F will not produce torque

(4) N will not produce torque

The total torque about pivot A provided by the forces shown in the figure, for L = 3.0 m, is

(1) 210 Nm

(2) 140 Nm

(3) 95 Nm

(4) 75 Nm

A solid disc rolls clockwise without slipping over a horizontal path with constant speed v. Then the magnitude of the velocities of points A, B and C with respect to the standing observer are respectively:

(1) v,v and v

(2) 2v, $\sqrt{2}$v and zero

(3) 2v, 2v and zero

(4) 2v, $\sqrt{2}$v and $\sqrt{2}$v

                   
1. \(\dfrac{\rho L^3}{8\pi^2}\)
2. \(\dfrac{\rho L^3}{16\pi^2}\)
3. \(\dfrac{5\rho L^3}{16\pi^2}\)
4. \(\dfrac{3\rho L^3}{8\pi^2}\)

The one-quarter sector is cut from a uniform circular disc of radius \(R\). This sector has a mass \(M\). It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation will be: 
                  

A uniform rod of length 2L is placed with one end in contact with the horizontal and is then inclined at an angle $\alpha$ to the horizontal and allowed to fall without slipping at contact point. When it becomes horizontal, its angular velocity will be

(1) $\omega =\sqrt{\frac{3g \sin \alpha }{2L}}$

(2) $\omega =\sqrt{\frac{2L}{3g \sin \alpha }}$

(3) $\omega =\sqrt{\frac{6g \sin \alpha }{L}}$

(4) $\omega =\sqrt{\frac{L}{g \sin \alpha }}$

A billiard ball of mass m and radius r, when hit in a horizontal direction by a cue at a height h above its centre, acquires a linear velocity $v_0$ . The angular velocity ${\omega }_0$ acquired by the ball will be:

1. $\frac{5v_0{r}^2}{2h}$

2. $\frac{2v_0{r}^2}{5h}$

3. $\frac{2v_{0}h}{5r^2}$

4. $\frac{5v_{0}h}{2r^2}$