Page 191 - Basic Electrical Engineering

Since R is variable, for determining the condition for maximum power
L
transfer from the source to the load, we will differentiate P with respect to
L
R .
L

Figure 2.100

i.e., we will make

Thus,

or,

or,

2
or, 2R (R + R ) = (R + R ) 3
L
i
i
L
L
or, 2R = R + R i
L
L