A circuit connected to an ac source of $emf e=e_0 \sin (100t)$ with $t$ in seconds, gives a phase difference of $\frac{\pi}{4}$ between the emf $e$ and current $i$. Which of the following circuits will exhibit this?

$RC$ circuit with $R= 1 kW$ and $C = 10 iF$

$tan \phi = \frac{X}{R} $ 

$ R = 1000\Omega , \Omega = 100$

For $\phi = \frac{\pi}{4} , X = R = 1000\omega$

This is true when $C = 10\mu F$