In practice, the plates are usually oppositely charged and at very high potentials.

The negative sign arises in the potential term since the proton and electron are oppositely charged.

The paper may or may not be oppositely charged.

This energy will be released to a locally, oppositely charged region in the form of lightning.

The object being painted is charged oppositely or grounded.

The charge carriers remain in these states for a long time until they recombine with an oppositely charged carrier.

Any ions caught inbetween would be pushed to the oppositely charged plate.

The solution is put into a syringe and aimed at an oppositely charged collector plate.

The oppositely charged regions create an electric field within the air between them.

Since the grounded bell is charged oppositely, this attracts the ball towards it.