A resistor is a device that limits current flow. The voltage that is dropped across a resistor can be determined by Ohm's law. Energy is given off from a resistor as heat, the power being equal to the resistance times the square of the current. A capacitor is a device that resists a change in voltage. A capacitor stores energy and returns it to the circuit as it charges and discharges.
Energy is stored in the form of electrical field.
Now we are going to learn about another elementary circuit component called an inductor . An inductor is a device that resists a change in current . An inductor stores energy and returns it to the circuit as it charges and discharges. Energy is stored in the form of a magnetic field . Units of inductance is the henry.