Question

a series resonance network consisting of a resistor of 300 ohms ,a capacitor of 120 micro f and an inductor of 20 mh is connected across a sinusoidal supply voltage which has a constant output of 9v at all frequency.calculate,the resonant frequency,the current at resonance, the voltage across the inductor and capacitor at resonance, the quality factor and the bandwidth of the circuit.also sketch the corresponding current waveform for all frequencies

Answer 1

The resonant frequency:

$$\omega=\dfrac1{\sqrt{LC}}=645.5\text{ rad/s}.$$

Current at resonance:

$$I=V/R=0.03\text{ A}.$$

The quality factor:

$$Q=\dfrac1{\omega RC}=0.043.$$

The voltages across the capacitor and inductor:

$$V=QI\omega L=0.0166\text {V}.$$