A coil is connected in series with a pure capacitor. The combination is fed from a 10 V supply of 10,000 Hz. It was observed that the maximum current of 2 Amp flows in the circuit when the capacitor is of value 1 micro farad. Find the parameters (R and L) of the coil.
This is the situation of resonance in A.C. Series circuit, for which XL = XC
Z = R = V/I = 10/2 = 5 ohms
If ω0 is the angular frequency, at resonance, L and C are related by ω02 = 1/(LC),
which gives L = 1/(ω02C) = 2.5 × 10−4H = 0.25mH
