In a laboratory experiment a student studies resonance in a series circuit containing…
PHYSICS · Subjective · CBSE · Physics · Alternating Current · Alternating Current
Problem
In a laboratory experiment a student studies resonance in a series circuit containing a fixed resistance R, a fixed inductance L and a variable capacitance C.
(i) Derive an expression for the angular frequency at which the current amplitude is maximum in terms of R, L and C.
(ii) Show that if the resistance is very small compared to the inductive and capacitive reactances at resonance, this frequency is practically equal to the natural angular frequency of the LC combination.
(iii) If the capacitance is increased by 4 % while R and L remain unchanged, estimate, to first order, the percentage change produced in the resonant angular frequency.