Question

A thin spherical shell with radius R1 = 3.00 cm is concentric with a larger thin spherical shell

with radius R2 = 5.00 cm. Both shells are made of insulating material. The smaller shell has

charge q1 = +6.00 nC distributed uniformly over its surface, and the larger shell has charge

q2 = - 9.00 nC distributed uniformly over its surface. Take the electric potential to be zero at an

infinite distance from both shells. (a) What is the electric potential due to the two shells at the

following distance from their common center: (i) r = 0; (ii) r = 4.00 cm ; (iii) r = 6.00 cm? (b) What

is the magnitude of the potential difference between the surfaces of the two shells? Which shell is

at higher potential: the inner shell or the outer shell?

Answer 1

$\varphi=k(\frac{q_1}{R_1}-\frac{q_2}{R_2})=250~V.$