A negatively charged particle with charge − q is far away from a positive charge + Q that is fixed in place. As - q moves closer to + Q,
(a) Does the electric field do positive or negative work?
(b) Does - q move through a potential increase or a potential decrease?
(c) Does the electric potential energy increase or decrease?
(d) Repeat questions (a)-(c) if the fixed charge is instead negative (− Q).