Question

A series combination of an inductor L, a capacitor C and a resistor R is connected across an ac source of voltage in a circuit. Obtain an expression for the average power consumed by the circuit. Find power factor for (i) purely inductive circuit, and (ii) purely resistive circuit.

A series LCR circuit with R = 20 Ω, L = 2 H and C = 50 μF is connected to a 200 volts ac source of variable frequency. What is (i) the amplitude of the current, and (ii) the average power transferred to the circuit in one complete cycle, at resonance ? (iii) Calculate the potential drop across the capacitor.

An alternating current I = 14 sin (100 πt) A passes through a series combination of a resistor of 30 Ω and an inductor of (2/5π) H. Taking √2 = 1.4, calculate the (i) rms value of the voltage drops across the resistor and the inductor, and (ii) power factor of the circuit.

Distinguish between reactance and impedance of an ac circuit. Show that an ideal inductor in an ac circuit does not dissipate any power.