A charged capacitor stores 10 C at 40 V.Its stored energy is:
A)400 J
B)200 J
C)4 J
D)2.5 J
E)1.25 J

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is given by the formula $E = \frac{1}{2}CV^2$, where $E$ is the energy in joules, $C$ is the capacitance in farads, and $V$ is the voltage in volts. Given $C = \frac{Q}{V} = \frac{10C}{40V} = 0.25F$ and $V = 40V$, substituting these values into the formula gives $E = \frac{1}{2} \times 0.25F \times (40V)^2 = 200J$.

A Charged Capacitor Stores 10 C at 40 V