Electric field inside a sphere varies with distance as Ar. Find the total charge enclosed within the sphere, if `A=3000 Vm^(-2)` and R=30cm`, where R is the radius of the sphere.

If the radius of a solid sphere is r unit, the total surface area of the quarter sphere is

If radius of a sphere be increased by 3 cm, the volume of the sphere is increased by 264 cc. Find the radius of the sphere.

If the volume of a hollow iron-sphere of thickness 3 cm be 490(2)/(7) cc , then find the external radius of the sphere.

The total flux phi comes out of a sphere of radius r. Keeping the amount of charge constant, if the radius of the sphere is made 2r, how much flux will come out of the sphere now?—

The electric field in a region is radially outward with a magnitude E=Ar where E = electric field, A is a constant = 100V//m^2 and r denotes the distance from the origin in meters. Find the charge contained in a sphere of radius 0.20 m centred as the origin.

Find the volume of the largest cylinder inscribed in the sphere of radius r cm.

The extremities of a diameter of a sphere lie on the positive y- and positive z-axes at distance 2 and 4, respectively. Show that the sphere passes through the origin and find the radius of the sphere.

The classical concept of atomic structure is that negative charges are uniformly distributed inside a sphere of radius R keeping the nucleus of positive charge Ze at the centre of that sphere. An atom as a whole is electrically neutral. find out the electric field at a distance r from the nucleus, according do this atomic model.