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Alternating Current — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsAlternating Current2 Marks
Question
Explain the root mean square value of alternating current.
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Answer

Root mean square value : The square root of the mean square of the instantaneous value of alternating curent is called the root mean square value $I_{\text {rms }}$ of the current. Root mean square value of alternating current is equal to the magnitude of direct current which shows the same heating effect as shown by alternating current. It is denoted by $I _{ rms }$.
$I _{ rms }=\frac{ I _0}{\sqrt{2}}$
$I _{ rms }=0.707 I _0$
It is clear from expression (1) that root mean square value of alternating current is $70.7 \%$ of its peak value.

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