Question

An inductor of inductance 100mH is connected in series with a resistance, a variable capacitance and an AC source of frequency 2.0 kHz. The value of the capacitance so that maximum current may be drawn into the circuit.

• A. 50 nF
• B. 60 nF
• C. 63 nF
• D. 79 nF

Answer 1

The correct option is C 63 nF

$C=\frac{1}{4{\pi }^2{f}^{2}L}$
$=\frac{1}{4\times 10\times 4\times {10}^6\times 100\times {10}^{-3}}$
$=\frac{1}{16}\times {10}^{-6}=\frac{1000}{16}\times {10}^{-9}$
= 63 nF