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 and 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.