Question

In Exercises 7.3 and 7.4, what is the net power absorbed by each circuit over a complete cycle. Explain your answer.

Answer 1

In the inductive circuit,

Rms value of current, I = 15.92 A

Rms value of voltage, V = 220 V

Hence, the net power absorbed can be obtained by the relation,

P=VI cos Φ 

Where, Φ= Phase difference between V and I

For a pure inductive circuit, the phase difference between alternating voltage and current is 90° i.e., Φ= 90°. Hence, P = 0 i.e., the net power is zero. In the capacitive circuit, rms value of current, I = 2.49 A rms value of voltage, V = 110 V Hence, the net power absorbed can be obtained as: P=VI cos Φ For a pure capacitive circuit, the phase difference between alternating voltage and current is 90° i.e., Φ= 90°. Hence, P = 0 i.e., the net power is zero.