The electric field strength at a far-off point P due to a point charge, +q located at the origin, O is 100 millivolts/meter. The point charge is now enclosed by a perfectly conducting hollow metal sphere with its centre at the origin, O. The electric field strength at the point, P
a) remains unchanged in its magnitude and direction
b) remains unchanged in its magnitude but reverse in direction
c) would be that due to a dipole formed by the charge, +q, at O and -q induced
d) would be zero
The charge will be reflected on the metal sphere. Now if we calculate the electric field because of the metal sphere then the same formula is used with distance from the center.