$Z_1$ and $Z_2$, as shown below:
$\theta$ is the argument of $Z_1$ and $\phi$ is the argument of $Z_2$.
Find the power dissipated in $Z_2$
If the phase of $Z_2$ ($\phi$) is fixed whilst allowing the magnitude to vary, find the relationship between $Z_1$ and $Z_2$ when we achieve maximum power transfer to $Z_2$.