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A metal rod of length $10 \mathrm{~cm}$ and a rectangular cross-section of $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$ is connected to a battery across opposite faces. The resistance will be
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maximum when the battery is connected across $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$ faces
Given, length, $l=10 \mathrm{~cm}$
Resistance of metal rod.
$R=\rho \cdot \frac{l}{A}$
i.e., $\quad R \propto \frac{1}{A}$
Since, among given faces in the options, area is minimum corresponding to face $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$. Hence, resistance will be maximum when the battery is connected across the face of dimension $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$.
Resistance of metal rod.
$R=\rho \cdot \frac{l}{A}$
i.e., $\quad R \propto \frac{1}{A}$
Since, among given faces in the options, area is minimum corresponding to face $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$. Hence, resistance will be maximum when the battery is connected across the face of dimension $1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$.
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