In which case would electrical potential energy be built up and stored in the electric field?

a
A positive charge is moved toward a negative charge.
b
A positive charge is moved toward a positive charge.
c
A negative charge is moved away from a negative charge.
d
none of the above

1 answer

You would have to PUSH a positive charge TOWARD another positive charge.
That means you would have to exert a force in the direction of motion - put positive work IN.
That INCREASES the potential energy stored. If you let go, they fly apart.