Question

A wire of length 11m and radius 7mm has a resistance of 10²ohms . what will be the resistivity of the material used to make this wire?​

Answer 1

Given:

$L= 11m$

$r = 0.007m$

$R= 100\Omega$

To find:

Resistivity of the material of wire

Solution:

We know that ; $R = \rho \frac{L}{A}$

where \rho is the resistivity of the wire.

$100 = \rho \frac{11}{0.007}$

$\frac{100\times 0.007}{11} = \rho$

$\therefore \rho = 63.63 \Omega m$

Hence of the material used to be make the wire is $63.63 \Omega m$.