Question

For an A.C given by $50\cos (100t+{45}^o)A$. The value of $I_{rms}=$_______ A

• A. Zero
• B. $50\sqrt{2}$
• C. $25$
• D. $25\sqrt{2}$

Answer 1

Answer: (D)

$25\sqrt{2}$

Comparing the equation by

$I=I_0\cos (\omega t+\varphi )$

Here, $I_0$ is the maximum peak voltage.

$I_0=50A$

The RMS voltage is obtained as:

$I_{rms}=\frac{I_0}{\sqrt{2}}$

$=\frac{50}{\sqrt{2}}=25\sqrt{2}A$

Option $D$ is the correct answer.