Question

The electrostatic potential (∅ᵣ) of a spherical symmetric
system kept at origin, is shown in the figure, and given as
∅ᵣ = q/4πℰ₀r (r ≥ R₀)
∅ᵣ = q/4πℰ₀R₀ (r ≤ R₀)
Which of the following option(s) is/are incorrect
(a) For spherical region r ≤ R₀ total electrostatic energy
stored is zero
(b) Within r = 2R₀ total charge is q.
(c) There will be no charge anywhere except at r = R₀
(d) None of these

Answer 1

Explanation:

A solid sphereical conductor of radius R has a spherical

cavity of radius a (a < R) at its centre. A charge + Q is kept

at the centre. The cahrge at the inner surface, outer and at a

position r (a < r < R) are respectively

(a) + Q, – Q, 0 (b) – Q, + Q, 0

(c) 0, – Q, 0 (d) + Q , 0, 0