In this video, David from Khan Academy derives the formula to find the power used by a resistor. [10:42]

A video explaining the difference between electrical potential (voltage) and electric potential energy. Learn that electrical potential energy is associated with a charge and electric energy is associated with a position. [8:55]

Sal Khan explains electric potential energy difference in a varying field in this video.

In this video, David from Khan Academy explains how to find the electric potential energy for a system of charges and solves an example problem to find the speed of moving charges. To see the calculus derivation of the formula watch this...

In this video, David from Khan Academy shows how to find the total electric potential at a point in space due to multiple charges.

The direction of an electrical field at a point is the same as the direction of the electrical force acting on a positive test charge at that point. This video demonstrates how to solve electrical field problems. [12:35]

Batteries power much of your daily life, so today we're going to talk about how they work. We're also explaining how terminal voltage results from the natural internal resistance of every real battery. [9:55]