Question

The sharpness of resonance in a series LCR resonant circuit, as the resistance of the circuit is increased, goes on

• A. increasing
• B. decreasing
• C. tends from zero to infinity
• D. tends from infinity to zero

Answer 1

The correct option is B decreasing

In a series LCR circuit, the quality factor which shows sharpness of resonance is given by,

$Q=\frac{1}{R}\sqrt{\frac{L}{C}}$

$\Rightarrow Q\propto \frac{1}{R}$

So, as the resistance of the circuit is increased, the sharpness of resonance goes on decreasing.

Hence, option $\left(B\right)$ is the correct answer.