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

The moment of inertia of a big drop is $I$. If $8$ droplets are formed from the big drop,then the moment of inertia of a small droplet is:

Two circular loops $P$ and $Q$ of radii $r$ and $nr$ are made respectively from a uniform wire. The moment of inertia of loop $Q$ about its axis is $4$ times that of loop $P$ about its axis. The value of $n$ is:

The moment of inertia of a sphere of mass $M$ and radius $R$ about an axis passing through its centre is $\frac{2}{5} M R^2$. The radius of gyration of the sphere about a parallel axis to the above and tangent to the sphere is

The moment of inertia of an object is effective during:

What is the moment of inertia of a thin circular disc about its diameter? ($M$ is the mass and $R$ is the radius of the disc.)