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Alternating Current — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsAlternating Current1 Mark
Question
Assertion : When capacitive reactance is smaller than the inductive reactance in $L C R$ current, e.m.f. leads the current .
Reason : The phase angle is the angle between the alternating e.m.f. and alternating current of the circuit.
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Answer

(b) The phase angle for the $L C R$ circuit is given by$\tan \phi=\frac{X_L-X_C}{R}=\frac{\omega L-1 / \omega C}{R}$Where $X, X$ are inductive reactance and capacitive reactance respectively when $X_{+}>X_c$ then $\tan \phi$ is positive i.e. $\phi$ is positive (between 0 and $\pi / 2$ ). Hence emf leads the current.

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