Answer
$\phi = 23.4^{\circ}$
Work Step by Step
We can find $\phi$:
$tan~\phi = \frac{X_L}{R}$
$tan~\phi = \frac{\omega_d~L}{R}$
$tan~\phi = \frac{2\pi~f_d~L}{R}$
$tan~\phi = \frac{(2\pi)~(60.0~Hz)~(0.230~Hz)}{200~\Omega}$
$tan~\phi = 0.4335$
$\phi = tan^{-1}~(0.4335)$
$\phi = 23.4^{\circ}$
