Question

As resistance in a series resonant circuit increases (i) sharpness of resonance decreases (ii) bandwidth increases

• A. both (i) and (ii) are true
• B. both (i) and (ii) are false
• C. (i) is true and (ii) is false
• D. (ii) is true and (i) is false

Answer 1

Answer: (A)

both (i) and (ii) are true

Answer 2

Sharpness of resonance of a series resonant circuit is given by , $Q = \frac{\omega_0 L}{R}$
If $R$ increases then $Q$ decreases.
Bandwidth of a series resonant circuit is given by $2 \Delta \omega = \frac{R}{L} = \frac{\omega_0}{Q}$
If $R$ increases then $\Delta \omega$ also increases