An Air-Filled 20- $\mu \mathrm { F }$ Capacitor Has a Charge Of

Multiple Choice

An air-filled 20- $\mu \mathrm { F }$ capacitor has a charge of $60 \mu \mathrm { C }$ on its plates. How much energy is stored in this capacitor?

A) $110 \mu \mathrm { J }$
B) $80 \mu \mathrm { J }$
C) $70 \mu \mathrm { J }$
D) $100 \mu \mathrm { J }$
E) $90 \mu \mathrm { J }$