Answer:
To find the peak value of a sinusoidal alternating current given its RMS (Root Mean Square) value, you can use the relationship between peak value and RMS value for a sinusoidal waveform.
The relationship is given by:
Peak Value = RMS Value * √2
In this case, the RMS value is 4.78 amp. Plugging this into the equation, we get:
Peak Value = 4.78 amp * √2 ≈ 6.76 amp
Therefore, the correct answer is option b) 6.76 amp.