Question
A $110 \,V$ $d.c$. heater is used on an $a.c.$ source, such that the heat produced is same as it produces when connected to $110 \,V$ $dc$ in same time-intervals. What would be the $r.m.s.$ value of the alternating voltage is .......... $V$
✓
Answer
(a)
Given that $H_{A C}=H_{D C}$
$I_{ ms }^2 R t=I^2 R t$
$\frac{V_{ ms }^2}{R}=\frac{V^2}{R}$
$V_{ rms }= V$
$\text { so } V_{ rms }=110 \,V$
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