Answer:
[tex]U=450 \ nJ[/tex]
Explanation:
[tex]\boxed{\left\begin{array}{ccc}\text{\underline{Formula's used to find the Energy Stored in a Capacitor:}}\\\\\ U=\frac{1}{2}Q \Delta V= \frac{1}{2}C\Delta V^2=\frac{Q^2}{2C} \end{array}\right }[/tex]
Given:
[tex]Q=30 \ nC \rightarrow 30 \times 10 ^{-8} \ C\\\\C= 10 \ nF \rightarrow 10 \times10^{-8} \ F[/tex]
Find:
[tex]U=?? \ J[/tex]
[tex]U=\frac{Q^2}{2C}\\\\\Longrightarrow U= \frac{(30 \times 10 ^{-8})^2}{2(10 \times10^{-8})}\\\\ \Longrightarrow U=4.5 \times10^{-7} \ J\\\\\therefore \boxed{\boxed{U=450 \ nJ}}[/tex]
Thus, the energy stored in the capacitor is found.