If the instantaneous current in a circuit is given by I = A sin (wt) ampere, the RMS value of the current is:
Correct answer: B. A/√2
- A. 2A
- B. A/√2
- C. 2√2A
- D. Zero
Explanation
The instantaneous current is given by I = A sin (wt). Here, A represents the peak current Imax. The RMS (Root Mean Square) value of an AC current is calculated using the formula Irms = Imax / √2. Therefore, substituting Imax = A, we get Irms = A/√2.Option A (2A) is incorrect as it does not follow the RMS formula. Option C (2√2A) is incorrect for the same reason as it does not align with the RMS calculation. Option D (Zero) is incorrect because a non-zero peak current cannot have an RMS value of zero.
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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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