The no-load current drawn by a transformer exhibits characteristics where________________?
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Answer: A. lags behind the voltage by about 75°
Explanation
Transformer no load current supplies the magnetic core excitation and consists of a very high inductive reactance component. The highly inductive nature of the iron core causes the excitation current vector to lag significantly behind voltage. Standard transformer calculations show that this no load current typically lags the applied voltage by approximately seventy five degrees. No load current comprises both a magnetizing component in quadrature and a core loss component in phase with voltage. Because the magnetizing reactance is extremely high, the reactive component dominates the total no load phasor sum. This lagging current creates the necessary alternating magnetic flux required to induce primary and secondary voltages.
Leading voltage phase angles occur in capacitive circuits rather than inductive transformer core excitation systems. A fifteen degree lag represents a circuit with a very high power factor unlike a transformer magnetizing branch. Option A accurately describes the typical seventy five degree lagging phase angle observed in transformer no load operation.
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- Engineering
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- Electrical Engineering
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