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A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z', the power drawn will be

1. P R / Z
2. P (R / Z)
3. P
4. P (R / Z)^2

Correct answer: P (R / Z)^2

Solution

The power drawn in an AC circuit is proportional to the square of the ratio of resistance to impedance, i.e., (R/Z)^2. Hence, the power becomes P (R/Z)^2.

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