A charge of 100 nC resides on the surface of a spherical shell of radius 20 cm.The electric potential at a distance of 15 cm from the center of the spherical shell is
A)18 V
B)180 V
C)1800 V
D)18,000 V
E)None of these is correct.

Question

Quizplus · Accepted Answer

For points inside a conducting shell (distance less than the radius of the shell), the electric potential is constant and equal to the potential on the surface of the shell. The potential at a distance (r) from a point charge (Q) in vacuum is given by $V = \frac{kQ}{r}$, where $k$ is Coulomb's constant ($8.987 \times 10^9 \, \text{Nm}^2/\text{C}^2$). Since the question asks for the potential at a distance less than the radius of the shell, we calculate the potential at the surface (r = 20 cm = 0.2 m) using the given charge (Q = 100 nC = 100 \times 10^{-9} C). Thus, $V = \frac{(8.987 \times 10^9)(100 \times 10^{-9})}{0.2} = 4493.5 \, V$, which is not listed among the options, making E the correct choice.

A Charge of 100 NC Resides on the Surface of a Spherical