Resistance $n$, each of $r\; ohm$, when connected in parallel give an equivalentresistance of $R\; ohm$. If these resistances were connected in series, the combination would have a resistance in $ohms$, equal to
A$R/n$
B$R/n^2$
C$nR$
D$n^2R$
AIPMT 2004, Medium
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D$n^2R$
d According to question $R=\frac{r}{n}$
$\Rightarrow r=n R$
$R_{\text {series }}=n r=n^{2} R$
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