Question

A series resonant $LCR$ circuit has a quality factor ($Q$-factor) 0.4. If $R = 2\, k\Omega, C = 0.1 \, \mu F$, then the value of inductance is

• A. 0.1 H
• B. 0.064 H
• C. 2 H
• D. 5 H

Answer 1

Answer: (B)

0.064 H

Answer 2

$Q = \frac{1}{R} \sqrt{\frac{L}{C}}$ or $\frac{L}{C} = (QR)^2$
$\therefore \:\:\: L = (0.4 \times 2 \times 10^3)^2 \times 0.1 \times 10^{-6} = 0.064 \, H$