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.
a. (i) Calculate the quality factor Q for each circuit.
b. (ii) Determine the resistance present in Circuit A and in Circuit B.
c. (iii) On a common set of axes, draw labelled sketches of the expected resonance curves for the two circuits.
d. (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.