A rigid body is in pure rotation, that is, undergoing fixed axis rotation. Then, which of the following statement(s) are true.

The moment of inertia of a thin square plate $ABCD$ of uniform thickness about an axis passing through the centre $O$ and perpendicular to the plane of the plate is $I.$ Which of the following is false?

A rod bent at right angle along its centre line, is placed on a rough horizontal fixed cylinder of radius $R$ as shown in figure. Mass of rod is $2 \mathrm{m}$ and rod is in equilibrium. Assume that friction force on rod at $A$ and $B$ are equal in magnitude.

A clockwise torque of $6 \mathrm{Nm}$ is applied to the circular cylinder as shown in the figure. There is no friction between the cylinder and the block.

Illustrated below is a uniform cubical block of mass $M$ and side $a.$ Mark the correct statement(s).

A massless spool of inner radius $r,$ outer radius $R$ is placed against vertical wall and tilted split floor as shown. A light inextensible thread is tightly wound around the spool through which a mass $m$ is hanging. There exists no friction at point $A,$ while the coefficient of friction between spool and point $B$ is $\mu .$ The angle between two surfaces is $\theta .$