Resonance, Bandwidth & Q Factor
Which one of the following graphs correctly represents the variation of impedance of a series LCR circuit with the frequency of applied a.c.?

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Answer: (b)
- As , is very large, so is large.
- At , and (minimum, not zero).
- For large , is large, so rises again.
- Graph B shows high , a dip to a non-zero minimum, then high . So the answer is (b) B.