A hollow conducting sphere of radius 12 cm has a net charge of 18 μC. What is the potential at the center of the sphere?

Question

Quizplus · Accepted Answer

The potential at the surface of a conducting sphere (and thus at any point inside, including the center) is given by $V = \frac{kQ}{r}$, where $k$ is Coulomb's constant ($9 \times 10^9 \, \text{Nm}^2/\text{C}^2$), $Q$ is the charge ($18 \times 10^{-6}\, \text{C}$), and $r$ is the radius ($0.12\, \text{m}$). Plugging in these values gives $V = \frac{(9 \times 10^9)(18 \times 10^{-6})}{0.12} = 1.35 \times 10^{6}\, \text{V}$, which is closest to the option written in scientific notation.

A Hollow Conducting Sphere of Radius 12 Cm Has a Net