If the peak voltage of an AC supply is 311 V, its rms value is about
Correct answer: B. 220 V
- A. 440 V
- B. 220 V
- C. 311 V
- D. 155 V
Explanation
Dividing 311 by the square root of 2, that is by about 1.414, gives roughly 220 V, the standard supply voltage in Pakistan. Multiplying instead gives the 440 V distractor. Half the peak, 155 V, has no physical significance here.
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About Phase of Alternating Current
Phase describes the position of an alternating voltage or current within its cycle and the phase difference between two sinusoidal quantities. The topic covers in phase signals, phase angle and lead or lag in resistive, inductive and capacitive circuits, rather than the amplitude or frequency of the supply.
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