Question

A wire of length 0.24 m and diameter $3.0\times {10}^{-5}$ m has a resistance of $160\Omega$. Calculate the resistivity of the material.?

• A. $4.7\times {10}^{-7}\Omega m$
• B. $9.7\times {10}^{-7}\Omega m$
• C. $8.7\times {10}^{-7}\Omega m$
• D. $6.7\times {10}^{-7}\Omega m$

Answer 1

The correct option is A $4.7\times {10}^{-7}\Omega m$

The resistivity is given by $\rho =R\ast \frac{A}{1}$
$=[160\times \pi \times (\frac{3}{2}\times {10}^{-5}{)}^2]/0.24=4.7\times {10}^{-7}\Omega m$