$A$ semi-circular disc has mass $M$ and radius $r$. The moment of inertia about an axis passing through its center and perpendicular to the plane of the disc is:

The moment of inertia of a solid sphere of density $\rho$ and radius $R$ about its diameter is

Two rings have their moments of inertia in the ratio $2:1$ and their diameters are in the ratio $2:1$. The ratio of their masses is

The ratio of the radius of gyration of a circular disc about an axis in its plane and tangent to it,to the radius of gyration of a circular ring about an axis in its plane and tangent to it is .........

If a wheel rotating with a constant angular speed experiences a break during its motion,what happens to its radius of gyration?

$A$ circular disc $X$ of radius $R$ is made from an iron plate of thickness $t$,and another disc $Y$ of radius $4R$ is made from an iron plate of thickness $\frac{t}{4}$. The ratio of the moment of inertia $\frac{I_Y}{I_X}$ is: