For a sinusoidal altrnating current, if the peak current is I ,the RMS current (I ) is:
Correct answer: A. I0 / √2
- A. I0 / √2
- B. I0 / 2
- C. √2 I0
- D. 2 I0
Explanation
The RMS (root-mean-square) current is the effective value of an AC current that delivers the same power as a DC current of the same magnitude. For a sinusoidal wave, the RMS value is the peak value I divided by √2 because the average of the square of the sine function over one cycle is 1/2. Thus, I0/ √2.
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About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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