## Maximum Power Theorem:

**Statement:** It states that the output power will be maximum, if external resistance R, connected to the source is equal to the internal resistance of the source.

**Proof:** Let us consider an electric circuit having battery E, key K and external resistance R, all connected in series. Let ‘r’ be the internal resistance of cell E and let I be the current flowing through the circuit then, the power dissipated in the circuit is given by **P = I ^{2}R**.