In Exercises 7.3 and 7.4, what is the net power absorbed by each circuit over a complete cycle. Explain your answer.
Solution and Explanation
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.
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Concepts Used:
AC Voltage
When voltage changes its direction after every half cycle is known as alternating voltage. The current flows in the circuit at that time are known as alternating current. The alternating current(AC) follows the sine function which changes its polarity concerning time. Most of the electrical devices are operating on the ac voltage.
