Question
A series resonant LCR circuit has a quality factor ( Q-factor) 0.4. If R = 2 kΩ, C = 0.1 μF, then the value of inductance is
0.1 H
0.064 H
2 H
5 H
Solution
B.
0.064 H
The amplitude of the current is maximum at resonant frequency ωo . The quantity factor is given by
Q = =
where ωo = resonant frequency
Given:- R = 2kΩ = 2 × 103 Ω
C = 0.1 μF = 0.1 × 10-6 F
The quantity factor Q defined by
Q =
= (QR)2
∴ L = ( 0.4 × 2 × 103 )2 × 0.1 × 10-6
L = 0.064 H
