Two concentric spheres of radii `R` and `2R` are charged. The inner sphere has a charge if `1muC` and the outer sphere has a charge of `2muC` of the same sigh. The potential is `9000 V` at a distance `3R` from the common centre. The value of R is

Two uniformly charged concentric hollow spheres of radii R and 2 R are charged. The inner sphere has a charge of 1 muC and the outer sphere has a charge of 2 mu C of the same sign. The potential is 9000 V at a point P at a distance 3R from the common centre O. What is the value of R ?

A conducting sphere of radius r has a charge . Then .

two metal spheres of radii R_(1) and R_(2) are charged to the same potential. The ratio of charges on the spheres is

There are two concentric hollow conducting spherical shells of radii r and R ( R gt r) . The charge on the outer shell is Q. What charge should be given to the inner shell, so that the potential at a point P , at a distance 2R from the common centre is zero ?

The diameter of a hollow metallic sphere is 60 cm and the sphere carries a charge of 500 muC . The potential at a distance of 100 cm from the centre of the sphere will be

A sphere of radius R has a charge density sigma . The electric intensity at a point at a distance r from its centre is

Two connectric spheres of radii R and r have similar charges with equal surface charge densities (sigam) . The electric potential at their common centre is

Two conducting spheres of radii r_(1) and r_(2) are charged to the same surface charge density . The ratio of electric field near their surface is