Question

A and B are two concentric spherical shells. If A is given a charge + q while B is earthed as shown in figure, then :

• A. charge on the outer surface of shell B is zero
• B. the charge on B is equal and opposite to that of A
• C. the field inside A and outside B is zero
• D. all of the above

Answer 1

The correct option is D all of the above

The total charge inside of each shell is zero. According to this the charges will be distributed among surfaces of shells as shown in figure.
When B is earthed, the charge on outer surface becomes zero.
Since, charge inside each shell is zero so the charge on inner surface of B is equal and opposite to that of outer surface of A and field inside each shell will be zero.
Ans : A, C