Question

How do you know if the electric potential is positive or negative?

Answer 1

Electric potential is positive:

1. A positive charge always has a positive potential surrounding it.
2. The potential falls and becomes closer to zero as you travel farther away from the charge. It becomes less positive as you get farther away.

Electric potential is negative:

1. A negative charge always has a negative potential.
2. The potential grows as you get farther away from the charge, becoming less negative as you get closer to it and eventually reaching zero.

Therefore,

1. If the two charges are of the same type (either positive or negative), the electric potential between them is positive.
2. If the charges are of different types, the electric potential between them is negative.
3. Negative potential denotes that the conservative force's work in moving a unit positive charge from infinity to that location in the electric field is positive.
4. The work done by the conservative force in moving a unit positive charge to infinity from that location in the electric field is negative, resulting in positive potential.

Hence, this is the way to know if the electric potential is positive or negative.