Question

When an a.c. source of e.m.f. $E=E_0\sin 100t$ is connected across a circuit, it is observed that voltage leads the current by a phase angle $\frac{\pi }{4}$. If the circuit consists possible only R-L, R-C or L-C in series the two elements could be.

• A. $R=10\Omega ,L=10mH$
• B. $R=10\Omega ,C=1000\mu F$
• C. $R=100\Omega ,C=1000\mu F$
• D. $R=10\Omega ,L=100mH$

Answer 1

The correct option is A $R=10\Omega ,L=10mH$

Circuit is inductive
$\tan \frac{\pi }{4}=\frac{\omega L}{R}$.