Question

​​​​​​A metallic spherical shell has an inner radius R1 and outer radius R2. A charge is placed at the centre of the spherical cavity. the surface charge density on the inner surface is:

Answer 1

The correct option of this question is (b).

Explain : When a charge +q is placed at the centre of spherical cavity as shown in figure,

Charge induced on the inner surface of shell

= -q

charge induced on the outer surface of shell

= +q

So, Surface charge density on the inner surface = \(\frac {-q}{4 \pi {R_1^2}}\)