Question

Three concentric metallic shells A, B and C of radii a, b and c (a < b < c) have surface charge densities +σ, –σ and +σ respectively as shown in the figure.

If shells A and C are at the same potential, then obtain the relation between the radii a, b and c.

Answer 1

Potential of shell A : Any point on the shell A lies inside the shells B and C.

Any point on B lies outside the shell A and inside the shell C. Potential of shell B,

Any point on shell C lies outside the shells A and B. Therefore, potential of shell C.