## Objective: Verification of Maximum power transfer theorem.

Maximum power is transferred from a source of given voltage and an internal impedence to the load impedence Z_{L }in a circuit (Fig.-1) under three conditions.

## (A) When only X_{L} is adjustable:

Under this condition the power consumed by the load (I^{2}*R_{L}) is maximum, when I is maximum, since R_{L }is constant.

This means that if the load reactance(X_{L}) is made equal magnitude and opposite in sign to the internal reactance(X_{i}), the power transferred is maximum.

## (B) When only R_{L} is adjustable:

From equation (1) in section (a), one may write,

Differentiating the equation ( 3 ) w.r.t R_{L }and equating to zero, one obtains.

## (C) When both R_{L} and X_{L} are adjustable:

Under this condition both equation (2) are valid simultaneously and one obtains.

##

Fig.-1.