Question

a 30 - μf capacitor is charged to 200 v. its stored energy is
o 0.15 j
o 0.6 j
o 6 j
o 6000 j
o 0.0006 j
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25.4 energy stored in an electric field

Explanation:

Step1: Recall energy - formula for capacitor

The formula for the energy stored in a capacitor is $U=\frac{1}{2}CV^{2}$, where $C$ is the capacitance and $V$ is the potential - difference across the capacitor.

Step2: Convert capacitance to SI units

Given $C = 30\ \mu F=30\times10^{- 6}\ F$ and $V = 200\ V$.

Step3: Substitute values into formula

$U=\frac{1}{2}\times(30\times10^{-6}\ F)\times(200\ V)^{2}$.
First, calculate $(200)^{2}=40000$. Then, $\frac{1}{2}\times30\times10^{-6}\times40000$.
$\frac{1}{2}\times30\times40000\times10^{-6}=600000\times10^{-6}$.
$U = 0.6\ J$.

Answer:

0.6 J