Q. A hollow metallic sphere of radius 10 cm is given a charge of 3.2 × 10-9C. The electric field intensity at a point 4 cm from the center is
(a) 9 × 10-9 NC-1
(b) 288 NC-1
(c) 2.88 NC-1
Sol: As there is no charge inside the sphere , hence electric field intensity inside the sphere is zero .