The densities of two solid spheres A and B of the same radii R vary with radial distance r as  and  , respectively, where k is a constant. The moments of inertia of the individual spheres about axes passing through their centres are IA and IB, respectively. If , the value of n is

Four identical solid spheres each of mass 'm' and radius 'a' are placed with their centres on the four corners of a square of side 'b'. The moment of inertia of the system about one side of square where the axis of rotation is parallel to the plane of the square is :

The moment of inertia of a uniform solid sphere about its diameter is

From a solid sphere of mass M and radius R a cube of maximum possible volume is cut. Moment of inertia of cube about an axis passing through its center and perpendicular to one of its faces is

Mass per unit area of a circular disc of radius a depends on the distance r from its centre as σ(r) = A + BrThe moment of inertia of the disc about the the axis, perpendicular to the plane and passing through its centre is :

A solid sphere of radius R𝑅 has a charge Q𝑄 distributed in its volume with a charge density ρ𝜌 =kra=𝑘𝑟𝑎, where k𝑘 and a𝑎 are constants and r𝑟 is the distance from its centre. If the electric field at r=𝑟= R2𝑅2 is 1818 times that at r=R,𝑟=𝑅, the value of a𝑎 is