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What is the r.m.s. value of the current for the A.C. current I=100 cos(200t+45°) A?

Asked in GSEB Board July 2017 · RMS and mean values

Answer: (1) 50√2 A

Step-by-step solution

Given: I=100 cos(200t+45°) A, so the peak value is I₀=100 A.

Idea: for any sinusoidal current Iᵣₘₛ=(I₀)/(√2). The frequency and the phase angle 45° do not affect it.

Iᵣₘₛ=(100)/(√2)=(100√2)/2=50√2 A.

That is about 70.7 A.

So the r.m.s. current is 50√2 A.

Why the other options are wrong

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