Current in an alternating circuit is ahead of voltage by a phase difference of π/3 . The alternating circuit is
Answer & explanation
Correct answer: option 1
The correct answer is option (1) : RC circuit
In alternating current circuits, the phase relationship between current and voltage depends on the components present in the circuit.
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In a pure resistive circuit, current and voltage are in phase (phase difference = 0).
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In a pure capacitive circuit, current leads voltage by π/2.
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In a pure inductive circuit, current lags voltage by π/2.
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In an LC circuit, the phase difference is either 0 at resonance or depends on the net reactance, but it is not π/3.
However, in circuits that contain both resistance and reactance (such as RC or LR circuits), the phase difference can take any value between 0 and π/2.
In an RC circuit, the current leads the voltage, and the phase angle is given by
tan φ = Xᶜ / R
Thus the phase angle can lie in the range
0 < φ < π/2
Since π/3 (60°) lies within this range, such a phase difference is possible in an RC circuit.
Checking the other options:
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LC circuit: current and voltage are either in phase at resonance or determined by net reactance, but not specifically π/3.
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LR circuit: current lags voltage, not ahead.
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L circuit: current lags voltage by π/2.
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