If a charge `– 150` nC is given to a concentric spherical shell and a charge `+50` nC is placed at its centre then the charge on inner and outer surface of the shell is

Options

A. `-50 nC, -100 nC`
B. `+50, nC, -200 nC`
C. `-50 nC, -200 nC`
D. 50 nC, 100 nC

Answer

A

Explanation

Whenever a charge `(-50 nC)` is kept inside a hollow metallic spherical shell, it induces an equal and opposite charge on the inner surface and an equal and same type of charge on the outer surface.
`:.` Inside, induced charge is -50 nC and outside, +50NC. As -150 Nc charge is already present outside, hence net charge on outer surface is -100 nC.