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Alternating Current — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsAlternating Current3 Marks
Question
Explain why the reactance offered by an inductor increases with increasing frequency of an alternating voltage.
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Answer

The inductive reactance is given by $\text{X}_\text{L}=2\ \pi\text{fL}, X_L$ is proportional to the frequency and current is inversely proportional to the reactance. An inductor opposes the flow of current through it by developing a back emf according to Lenz’s law. If the current is decreasing, the polarity of the induced emf will be so as to increase the current and vice$-$versa.
Since, the induced emf is proportional to the rate of change of current.

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