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Question
Choose the correct answer from given options
The selectivity of a series LCR a.c. circuit is large, when
Options
L is large and R is large
L is small and R is small
L is large and R is small
L = R
Solution
Selectivity of a circuit depends on the quality of resonance. The quality factor is given by: `Q = (w_0L)/R`
High value of quality factor make sure that the resonance curve is sharp. Sharper the resonance curve is more selective is the LCR circuit. Thus, the selectivity of the LCR circuit is large when L is large and R is small.
Hence, the correct answer is option L is large and R is small.
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