A wire of length 25 m and cross-sectional area $5 \mathrm{~mm}^2$ having resistivity of $2 imes 10^{-6} \Omega \mathrm{~m}$ is bent into a complete circle. The resistance between diametrically opposite points will be

Question

A wire of length 25 m and cross-sectional area $5 \mathrm{~mm}^2$ having resistivity of $2 	imes 10^{-6} \Omega \mathrm{~m}$ is bent into a complete circle. The resistance between diametrically opposite points will be

Aicharya · Accepted Answer

$\begin{aligned}
& \mathrm{L}=25 \mathrm{~m}, \mathrm{~A}=5 \mathrm{~mm}^2=5 \times 10^{-6} \mathrm{~m}^2 \\ & \rho=2 \times 10^{-6} \Omega \mathrm{~m} \\ & \mathrm{R}_{\text {wire }}=\frac{\rho \mathrm{L}}{\mathrm{~A}}=\frac{2 \times 10^{-6} \times 25}{5 \times 10^{-6}}=10 \\ & \mathrm{R}_{\mathrm{eq}}=\frac{\mathrm{R}}{4}=\frac{10}{4}=2.5 \Omega
\end{aligned}$
Answer does not match with NTA option.

A wire of length 25 m and cross-sectional area $5 \mathrm{~mm}^2$ having resistivity of $2 \times 10^{-6}…

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