# Solved Problems-5

Problems-5

**A 20**Î©

**resistor is connected in series with an inductor, a capacitor and an ammeter across a 25 V variable frequency supply. When the frequency is 400 Hz, the current is at its maximum value of 0.5 A and the potential difference across the capacitor is 150 V. Calculate:**

- The capacitance of the capacitor.
- The resistance and inductance of the inductor.

Solution

Here,

*R*= 20 Î©,*V*= 25 Volt,_{m}*f*= 400 Hz,*I*= 0.5 A,*V*= 150 Volt_{C}When the current is the maximum, the circuit is in resonance and hence total reactances

*X*~

_{L}*X*= 0

_{C}- The capacitance value is calculated as,
- âˆµ
*X*~_{L}*X*= 0_{C}*X*=_{L}*X*_{C}_{}â‡’

Also, at resonance, circuit resistance = circuit impedance

Let,

*r*= resistance of the inductorThen