A hollow metallic sphere of radius R is given a charge Q. Then, the potential at the centre is :
A point charge q is placed inside a conducting spherical shell of inner radius 2R and outer radius 3R at a distance of R from the centre of the shell. The electric potential at the centre of shell will be times.
A ring with a uniform charge Q and radius R, is placed in the y−z plane with its centre at the origin(k=14πε0). Then :
A half ring of radius R has a charge of λ per unit length. The potential at the centre of the half ring is(k=14πε0)