A point charge is released from rest in a region containing an electric field. The charge will start to move
a. in a direction that makes its potential energy increase
b. in a direction that makes its potential energy decrease
c. along a path of constant potential energy
d. Either a or b, depending on the sign of the point charge
b) in a direction that makes its potential energy decrease.
Explanation:
As the electric field has the direction that would take a positive test charge under its sole influence, the positive test charge, will have an increase in its kinetic energy.
Due to the conservation of energy, in absence of non-conservative forces, this increment must be equal and opposite to the change in electric potential energy, which will be always negative, independent of the sign of the charge.
