Question

A material wire is having the length 10m and cross-section area 1 mm2

is having the resistance

20 then find the resistivity of the material of the wire?​

Answer 1

$\large\underline{\bigstar{\sf Given-}}$

• Lenght of wire $(\ell)$ = 10m
• Cross-section Area (A) = 1mm² or ${\sf 10^{-6}m^2}$
• Resistance (R) = 20Ω

$\large\underline{\bigstar{\sf To \: Find-}}$

• Resistivity $(\rho)$

$\large\underline{\bigstar{\sf Formula \: Used-}}$

$\color{violet}\bullet\underline{\boxed{\sf R=\rho\dfrac{\ell}{A}}}$

$\large\underline{\bigstar{\sf Solution-}}$

$\implies{\sf 20=\rho\dfrac{10}{10^{-6}} }$

$\implies{\sf \rho = \dfrac{20×10^{-6}}{10} }$

$\color{red}\implies{\sf \rho = 2×10^{-6}\:Ω.m}$

$\large\underline{\bigstar{\sf Answer-}}$

Resistivity of wire is $\color{red}{\sf 2×10^{-6}Ω.m}$