Question

A source $V_s\left(t\right)=Vcos100\pi t$ has an internal impedance of 4 + j3 $\Omega$. If a purely resistive load connected to this source has to extract the maximum power out of the source, its value in $\Omega$ should be

• A. 3
• B. 4
• C. 5
• D. 7

Answer 1

The correct option is C 5

For pure resistive load to extract the maximum power

$R_L=\sqrt{R_s^2+X_s^2}=\sqrt{4^2+3^2}$

$R_L=5\Omega$