Question

An A.C. source of voltage $\text{V} = 100 \, sin \left(\right. 100 \, \text{\pi t} \left.\right)$ is connected to a resistor of resistance $20 \, \, \Omega $ . The rms value of current through resistor is

• A. $\text{10 A}$
• B. $\frac{\text{10}}{\sqrt{2}} \text{ A}$
• C. $\frac{\text{5}}{\sqrt{2}} \text{ A}$
• D. $\text{None of these}$

Answer 1

Answer: (C)

$\text{I}_{0} = \frac{\text{V}_{0}}{\text{R}} = \frac{\text{100}}{\text{20}} = \text{5 A}$
$\therefore \text{I}_{\text{rms}} = \frac{\text{I}_{0}}{\sqrt{2}} = \frac{5}{\sqrt{2}} \text{ A}$