- 2019:
Q11. A series LCR circuit with L = 1.0 H, C = 2.0 μF and R = 50Ω is connected to a variable frequency 220 V ac source. Calculate the Q-factor of the circuit at resonance.
The Q-factor of a series LCR circuit is given by
$$Q = \frac{1}{R\sqrt{LC}}$$
Substituting the values of L, C, and R, we get
$$Q = \frac{1}{50\sqrt{1.0\times2.0\times10^{-6}}} = 31.6$$
Therefore, the Q-factor of the circuit at resonance is 31.6.
- 2018:
Q3. An LCR circuit is in resonance. If the resistance is increased, the current in the circuit will: (A) increase (B) decrease (C) remain the same (D) become zero
The answer is (B).
When an LCR circuit is in resonance, the current in the circuit
