Question

A switch that connects a battery to a 10 mF capacitor is closed. Several seconds later you find that the capacitor plates are charged to $\pm$30 mC. What is the emf of the battery?

Short answer

The emf of battery is$3V$.

Step-by-step solution

Given information

We have given that the capaciter batter is charged to $\pm 30mC$.

We need to find the emf of the battery.

Explanation

In this problem, we have to find the emf of the battery, which means voltage of the battwery. Using$Q=CV$formula to solve for $V$.

$Q=CV\to V=\frac{Q}{C}\to \frac{30\times {10}^{-6}C}{10\times {10}^{-6}F}=3V$