1)

The value of inductance L for which the current is maximum  in series LCR circuit with C=10 $\mu$ F  and ω= 1000 rad/s


A) 10 mH

B) 50 mH

C) 200 mH

D) 100 m H

Answer:

Option D

Explanation:

 Maximum current flows in the circuit in resonance condition Current in the LCR circuit 

$i=\frac{V}{\sqrt{R^{2}+(X_{L}-X_{C})^{2}}}$

 For current to be maximum denominator should be minimum

$(X_{L}-X_{C})^{2}$= 0

$\Rightarrow X_{L}=X_{C}\Rightarrow\omega L=\frac{1}{\omega C}$


$\therefore$   $ L=\frac{1}{\omega^{2}C}=\frac{1}{(100)^{2}\times10\times 10^{-6}}$

$ L=\frac{1}{10}H=0.1 H=100 mH$