Two solid conductors are made up of same material, have same length and same resistance. One of them has a circular cross section of area $A_{1}$ and the other one has a square cross section of area $A_{2}$. The ratio $\frac{A _{1}}{A _{2}}$ is
NEET 2020, Easy
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Resistance of conductor is given as
$R=\frac{\rho l}{A}$
$\therefore \quad A=\frac{\rho l}{R}$
$\Rightarrow \frac{A_{1}}{A_{2}}=\frac{\rho_{1}}{\rho_{2}} \times \frac{L_{1}}{I_{2}}\left(\frac{R_{2}}{R_{1}}\right)$
$\Rightarrow \frac{A_{1}}{A_{2}}=1 \quad\left[\because R_{1}=R_{2}, I_{1}=l_{2}\right.$ and for same
material $\left.\rho_{1}=\rho_{2}\right]$
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