PhysicsLAB: Electric Potential

Just as PE (potential energy) transforms to KE (kinetic energy) for a mass lifted against the gravitational field (left), the electric PE of an electric charge transforms to other forms of energy when it changes location in an electric field (right).

When released, how does the KE acquired by each compare to the decrease in PE?

Refer to the following information for the next five questions.

A force compresses the spring. The work done in compression is the product of the average force and the distance moved. W = Fd. This work increases the PE of the spring.

Similarly, a force pushes the charge (call it a test charge) closer to the charged sphere.

The work done in moving the test charge is the product of the average ____

and the ____ moved.

W =

This work ____ the PE of the test charge.

If the test charge is released, it will be repelled and fly past the starting point. Its gain in KE at this point is ____ to its decrease in PE.

At any point, a greater quantity of test charge means a greater amount of PE, but not a greater amount of PE per quantity of charge. The quantities PE (measured in joules) and PE/charge (measured in volts) are different concepts.

By definition: Electric Potential = PE/charge.
1 volt = 1 joule / 1 coulomb

Electric PE/charge has the special name electric ____.

Since it is measured in volts it is commonly called ____.

If a conductor connected to the terminal of a battery has a potential of 12 volts, then each coulomb of charge on the conductor has a PE of ____.

Some people get mixed up between force and pressure. Recall that pressure is force per area. Similarly, some people get mixed up between electric PE and voltage. According to this chapter, voltage is electric PE per ____.