Two identical coils ( ) and identical capacitors ( ) are used in two separate series…
PHYSICS · Multi-part · CBSE · Physics · Alternating Current · Alternating Current
Problem
Two identical coils (L=20mH) and identical capacitors (C=2.0μF) are used in two separate series LCR circuits, Circuit A and Circuit B. The only difference between them is their series resistance.
For Circuit A the current amplitude falls to Imax/2 at 4900 rad s⁻¹ and 5100 rad s⁻¹. For Circuit B the corresponding half-power points are 4800 rad s⁻¹ and 5200 rad s⁻¹.
(i) Calculate the quality factor Q for each circuit.
(ii) Determine the resistance present in Circuit A and in Circuit B.
(iii) On a common set of axes, draw labelled sketches of the expected resonance curves for the two circuits.
(iv) Which circuit would be more suitable for sharply selecting a single radio station in a tuning application? Give two clear reasons based on your calculations and sketches.