For a rectangle $ABCD$ with $BC = 2AB$,about which axis will the moment of inertia be minimum?

The ratio of the radius of gyration of a solid sphere of mass $M$ and radius $R$ about its own axis to the radius of gyration of a thin hollow sphere of the same mass and radius about its axis is:

Of the two eggs which have identical sizes,shapes and weights,one is raw and the other is half-boiled. The ratio between the moment of inertia of the raw egg to the half-boiled egg about their central axis is:

Two loops $P$ and $Q$ of radii $R_1$ and $R_2$ are made from uniform metal wire of the same material. If $I_P$ and $I_Q$ are the moments of inertia of loops $P$ and $Q$ respectively,then the ratio $R_1 / R_2$ is (Given $I_P / I_Q = 27$) (in $:1$)

Three bodies have equal masses $m$. Body $A$ is a solid cylinder of radius $R$,body $B$ is a square lamina of side $R$,and body $C$ is a solid sphere of radius $R$. Which body has the smallest moment of inertia about an axis passing through their centre of mass and perpendicular to the plane (in case of lamina)?

When ice at the poles of the Earth melts,its moment of inertia will ........ .