Question

A resistance of $20\Omega$ is connected to a source of alternating current rated $220\text{V}$, $50\text{Hz}$. Find the maximum instantaneous current in the resistor.

• A. $31\text{A}$
• B. $28.5\text{A}$
• C. $15.5\text{A}$
• D. $11\text{A}$

Answer 1

The correct option is C $15.5\text{A}$

Given:-

The $rms$ potential difference $=220\text{V}$

So, the $rms$ current is

$i_{rms}=\frac{220\text{V}}{20\Omega }=11\text{A}$

The maximum instantaneous current

$=\sqrt{2}{i}_{rms}$

$=\sqrt{2}\times 11\text{A}\approx 15.5\text{A}$

Hence, option $\left(C\right)$ is correct.