Given $n$ resistors each of resistance $$R, how will you combine them to get the $(i)$ maximum $(ii)$ minimum effective resistance? What is the ratio of the maximum to minimum resistance?
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Total number of resistors $= n$ Resistance of each resistor $= R$
  1. When n resistors are connected in series, effective resistance $R_1$ is the maximum, given by the product nR.
Hence, maximum resistance of the combination, $R_1 = nR$
  1. When n resistors are connected in parallel, the effective resistance $(R_2)$ is the minimum, given by the ratio $\frac{\text{R}}{\text{n}}.$
Hence, minimum resistance of the combination, $\text{R}_2=\frac{\text{R}}{\text{n}}$
  1. The ratio of the maximum to the minimum resistance is,
$\frac{\text{R}_1}{\text{R}_2}=\frac{\text{nR}}{\frac{\text{R}}{\text{n}}}=\text{n}^2$
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