A tuned detector circuit in a radio receiver consists of an inductor of
PHYSICS · Multi-part · CBSE · Physics · Alternating Current · Alternating Current
Problem
A tuned detector circuit in a radio receiver consists of an inductor of L=1.0mH, a variable capacitor of C=25nF and a series resistance of R=5Ω. The circuit is driven by an rf signal of rms voltage 2.0V whose frequency can be varied.
(i) Calculate the resonant frequency of the circuit.
(ii) Compute the rms current through the circuit at resonance.
(iii) Owing to the wiring and contacts, an additional resistance of 20Ω is introduced in series with the circuit. Re-calculate the rms current at resonance.
(iv) The detector requires a minimum rms current of 50mA to operate satisfactorily. State with reason whether it will operate in the cases of parts (ii) and (iii).