Question

The root mean square value of alternating current is equal to

• A. twice the peak value
• B. half the peak value
• C. $1/\sqrt{2}$ times the peak value
• D. peak value

Answer 1

Answer: (C)

$1/\sqrt{2}$ times the peak value

$i=i_0\sin \left(\omega t\right)$

$I_{rms}=\frac{1}{T}{\int }_0^T{i}^2{\sin }^2\left(\omega t\right)dt=\frac{i}{\sqrt{2}}$