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प्रश्न
An ac circuit as shown in the figure has an inductor of inductance L and a resistor or resistance R connected in series. Using the phasor diagram, explain why the voltage in the circuit will lead the current in phase.
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उत्तर

In inductor voltage leads current by π / 2 and in resistor both voltage and current are in same phase, the resultant of eL & eR will lead by phase Φ .
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Assertion: When the frequency of the AC source in an LCR circuit equals the resonant frequency, the reactance of the circuit is zero, and so there is no current through the inductor or the capacitor.
Reason: The net current in the inductor and capacitor is zero.
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