Question

An LCR series circuit is connected to an external e.m.f. $e = 200\sin 100\pi t$. The values of the capacitance and resistance in the circuit are $2\mu F$ and $100\Omega$ respectively. The amplitude of the current in the circuit will be maximum when the inductance is

• A. 100 Henry
• B. $50/\pi^{2}$ Henry
• C. 100 π Henry
• D. $100 \times \pi^{2}$Henry

Answer 1

Answer: (B)

$50/\pi^{2}$ Henry

Answer 2

Current will be maximum in resonance i.e. X_L = X_C­

⇒$100\pi \times L = \frac{1}{100\pi \times 2 \times 10^{- 6}}$⇒ $L = \frac{50}{\pi^{2}}Henry.$