Question

The potential energy of a charge q at position r in an external electric potential V(r) is given by:

Options

• \[U(r) = qV(r)\]

• \[U(r) = V(r) - q\]

• \[U(r) = \frac{q}{V(r)}\]

• \[U(r) = q^2 V(r)\]

Answer 1

The potential energy equals the work done in bringing charge q from infinity (where V = 0) to position r. Since the work for a unit charge is V(r), scaling by q gives \[U(r) = qV(r)\].