A non-uniformly charged ring is kept near an uncharged conducting solid sphere. The distance between their centres (which are on the same line normal to the plane of the ring) is 3 m and their radius is 4 m. If total charge on the ring is 1 μC, then the potential of the sphere will be

q = 1μC is the charge on ring. To find the potential of sphere, we find potential at the center of sphere, which will be same as the potential at any point on the surface of  sphere. It is because, electric field inside the sphere will be zero and sphere will be an equipotential body. Due to charge q on the ring, charges will be induced on the sphere but net charge of sphere will remain zero. Hence potential at the center of sphere due to induced charges on sphere will be zero. Potential at the center of sphere will be only due to charge of ring. So, VC=kq32+42=9×109×10−65       =1.8×103V=1.8kV