A 5.0 μF capacitor has a potential difference of $5.0 \mathrm {~V}$ applied across its plates. If the potential difference across its plates is increased to $8.0 \mathrm {~V}$ how much additional energy does the capacitor store?

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is given by $ U = \frac{1}{2} C V^2 $. Initially, $ U_1 = \frac{1}{2} \times 5.0 \times 10^{-6} \times (5.0)^2 = 62.5 \, \mu J $. After increasing the voltage, $ U_2 = \frac{1}{2} \times 5.0 \times 10^{-6} \times (8.0)^2 = 160 \, \mu J $. The additional energy stored is $ U_2 - U_1 = 160 \, \mu J - 62.5 \, \mu J = 97.5 \, \mu J $, which rounds to 98 μJ.

A 50 μF Capacitor Has a Potential Difference Of Of 5.0