Energy Stored by Capacitors
Equations
- You can use \(Q=CV\) to eliminate Q and V separately from the equation: \(W=\frac{1}{2}QV\) to get:
- \(W=\frac{1}{2}CV^2\)
- \(W=\frac{1}{2}\frac{Q^2}{C}\)
A 0.10 F capacitor is connected to a power supply and then removed. The energy stored in the capacitor is 25J. Calculate the initial p.d. across the capacitor.
- \(W=25J\)
- \(C=0.10F\)
- \(W=\frac{1}{2}CV^2\)
- \(25=\frac{1}{2}\times0.1\times V^2\)
- \(V=22V\) to 2sf