The ratio of the radius of gyration of a circular disc to that of a circular ring,each of the same mass and radius,about their respective central axes is:

Find the moment of inertia of a thin,massless rod about an axis passing through its centre of mass,where a pair of masses is suspended at both ends of this rod.

$A$ thin metal rod of mass $M$ and length $L$ is cut into four equal parts by cutting it perpendicular to its length. If the moment of inertia of the rod about an axis passing through its centre and perpendicular to its length is $I$,then the moment of inertia of each part about an axis passing through its own centre and perpendicular to its length is:

Two discs of same mass and same thickness $(t)$ are made from two different materials of densities $d_1$ and $d_2$ respectively. The ratio of the moment of inertia $I_1$ to $I_2$ of the two discs about an axis passing through the centre and perpendicular to the plane of the disc is:

Two circular discs of iron have the same thickness. The diameter of disc $A$ is twice that of disc $B$. The moment of inertia of $A$ will be ........ times that of $B$.

$A$ wire of length $\ell$ and mass $M$ is bent into a semicircle of radius $r$ as shown in the figure. Calculate the moment of inertia about the axis $XX'$.