Question

Quality factor of a series $LCR$ circuit decreases from 3 to 2. Resonant frequency is $600 \, Hz$. Change in band width is

• A. zero
• B. 100 Hz increase
• C. 100 Hz decrease
• D. 300 Hz increase

Answer 1

Answer: (B)

100 Hz increase

Answer 2

Relation between bandwidth and quality factor of series $LCR$ circuit for a given resonant frequency,
$\Delta\upsilon = \frac{\upsilon _{0}}{Q}$
$\upsilon_{0} = 600 Hz$
For $Q = 3, \Delta\upsilon = \frac{600}{3} = 200 Hz$
For $Q = 2, \Delta \upsilon = \frac{600}{3} = 300 Hz$