Question

Using \(Q=CV\), which expression is an equivalent form of \(U=\frac{Q^2}{2C}\)?

Options

• \[U=\frac{Q^2C}{2}=\frac{1}{2}C^2V^2\]

• \[U=\frac{1}{2}QV=\frac{1}{2}CV^2\]

• \[U=QV=CV^2\]

• \[U=\frac{Q}{2V}=\frac{C}{2}V\]

Answer 1

Substituting \(Q=CV\) into \(U=\frac{Q^2}{2C}\) gives \(U=\frac{1}{2}QV\). Replacing \(Q\) with \(CV\) also gives \(U=\frac{1}{2}CV^2\).