Question

If a wire has a resistance of 1.32 ohm a length of 110 cm and an area of cross section of 0.00415 cm square.Find the resistivity of wire in ohm law

Answer 1

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

• Resistance of wire (R) = 1.32 Ω
• Lenght of wire $(\ell)$ = 110cm
• Cross-section Area (A) = 0.00415cm²

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

• Resistivity $(\rho)$

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

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

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

$\implies{\sf 1.32=\rho×\dfrac{110×10^{-2}}{415×10^{-5}×10^{-4}}}$

$\implies{\sf 1.32=\rho\dfrac{110×10^{-2}}{415×10^{-9}} }$

$\implies{\sf \rho=\dfrac{1.32×415×10^{-9}}{110×10^{-2}} }$

$\implies{\sf \rho=\dfrac{547.8×10^{-19}}{110×10^{-2}}}$

$\color{red}\implies{\sf \rho=4.98×10^{-17}\:Ω.m }$

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

Resistivity of wire is $\color{red}{\sf 4.98×10^{-17}\:Ω.m}$