Mapping of equipotential lines 1) do the electric field lines cross? can two equipotential lines ever cross? explain 2) explain why the equipotential surfaces should be always perpendicular to the electric field lines? 3) a uniform electric field is parallel to the y-axis. what direction can a charge be displaced in this field without any external work being done on the charge? part 2: determination of the intensity of the electric field 1) plot the voltmeter reading v versus the distance d. 2) find the slope from this graph. how is it related to the electric field?