One solid sphere $A$ and another hollow sphere $B$ have the same mass and the same outer radii. Their moments of inertia about their diameters are $I_{A}$ and $I_{B}$ respectively. Which of the following relations is correct?

$A$ wire of mass $m$ and length $l$ is bent in the form of a circular ring. The moment of inertia of the ring about its axis is:

Radius of gyration of a thin uniform circular disc about the axis passing through its centre and perpendicular to its plane is $K_{c}$. Radius of gyration of the same disc about a diameter of the disc is $K_d$. The ratio $K_c: K_d$ is

Two point masses of $0.3 \ kg$ and $0.7 \ kg$ are fixed at the ends of a rod of length $1.4 \ m$ and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum is located at a distance of

We have a rectangular plate of uniform thickness. $E, F, G, H$ are the midpoints of $AB, BC, CD,$ and $AD$ respectively. About which axis will the moment of inertia be minimum?

The wheels of moving vehicles are made hollow in the middle and thick at the rim because...