In both cases force is being applied?

[Miraj Kayastha]

If a positive charge is pushed towards another positive charge then the potential energy of the system increases.

When negative charge attracts positive charge why doesn't the system gain potential energy?

In both cases force is being applied?

 

[Dale]

The direction of the force is opposite, so the work done is opposite and therefore the change in potential energy is opposite.

 

[Miraj Kayastha]

Does negative work done mean loss in potential energy?

 

[Dale]

Or loss in KE, yes.

 

[KingCrimson]

the system would be more stable if the negative charge was closer to the positive charge , so the work done * energy spent * was actually energy stored in the system that was released to pull the charges together