Alternating Current Question 8
Question 8 - 29 January - Shift 2
An inductor of inductance $2 \mu H$ is connected in series with a resistance, a variable capacitor and an $AC$ source of frequency $7 kHz$. The value of capacitance for which maximum current is drawn into the circuit is $\frac{1}{x} F$, where the value of $x$ is
(Take $\pi=\frac{22}{7}$ )
Show Answer
Answer: (3872)
Solution:
Formula: Resonant Frequency
$\frac{1}{2 \pi fC}=2 \pi fL$
$C=\frac{1}{4 \pi^{2} f^{2} L}=\frac{1}{4 \times \pi^{2} \times 49 \times 10^{6} \times 2 \times 10^{-6}}$
$C=\frac{1}{3872} F$
$x=3872$