Question

The current through a wire changes with time according to the equation $I=\sqrt{t}$. The correct value of the rms current within the time interval $t=2s$ to $t=4s$ will be

• A. $\sqrt{3}A$
• B. $3A$
• C. $3\sqrt{3}A$
• D. $noneoftheabove$

Answer 1

The correct option is A $\sqrt{3}A$

$I_{rms}={\left(\frac{1}{4-2}{\int }_{t=2}^{t=4}{I}^{2}dt\right)}^{1/2}$
$={\left(\frac{1}{2}{\int }_{t=2}^{t=4}tdt\right)}^{1/2}$
$=\sqrt{3}A$