If a $30\, V$, $90\, W$ bulb is to be worked on a $120\, V$ line, a resistance of how many ohms should be connected in series with the bulb ............... $ohm$
Medium
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(c) Suppose resistance $R$ is corrected in series with bulb. Current through the bulb $i = \frac{{90}}{{30}} = 3\,A$
Hence for resistance $V = i\,R$$ \Rightarrow $ $90 = 3 \times R \Rightarrow R = 30\,\Omega $
Hence for resistance $V = i\,R$$ \Rightarrow $ $90 = 3 \times R \Rightarrow R = 30\,\Omega $
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