if a positive charge were constrained to move along one of t

if a positive charge were constrained to move along one of the equipotential lines, would it speed up slow down or travel with a constant speed?

Solution

An equipotential surface have same electric potential. If a charge is to be moved between any two points on an equipotential surface, according to the formula dW=qdVdW=qdV, the work done becomes zero. due to this no change in energy. The kinetic and potential energy is constant. hence the speed of the positive charge is constant.