Question

The work done to bring a charge q from infinity to a point r, where the external potential is V(r), is:

Options

• \[\frac{V(r)}{q}\]

• \[\frac{q}{V(r)}\]

• \[qV(r)\]

• \[q^2 V(r)\]

Answer 1

The work done for a unit positive charge equals V(r); scaling by a factor of q gives \[qV(r)\] for charge q. This work is stored as the potential energy of the charge at position r.