Question

calculate the resistance of a metal wire of length 2m and area of cross section 1.55 x 10^-6 m^2, if the resistivity of the metal be 2.8 x 10^-8 ohm m

Answer 1

L =2m  ,  A =  1.55* 10^ -6  ,  

ROW= R*A/L

R= ROW*L/A

R = 2.8 * 10^ -8  *  2 / 1.55* 10^-6

R=  560/155 *10^-2

R = 3.61 *10^-2

Answer 2

Answer:

The resistance of the metal wire is $\bold{3.61 \times 10^{-2}}$

Explanation:

Given:

Length of metal wire = 2m  

Area of cross section = $1.55 \times 10^{-6} m^{2}$

Resistivity of metal = $2.8 \times 10^{-8} \text { ohm } \mathrm{m}$

We have to find the resistance of metal wire.

L=2m

A= $1.55 \times 10^{-6} m^{2}$

$\bold{\rho=\frac{R A}{L}}$

Therefore,

$\bold{\mathrm{R}=\frac{\rho L}{A}}$

Now, let us substitute all the known values in the above expression.

We get,

$R=\frac{2.8 \times 10^{-8} \times 2}{1.55 \times 10^{-6}}$

By simplification we get the above expression as,

$\begin{array}{l}{R=\frac{560}{1.55 \times 10^{-2}}} \\ {R=3.61 \times 10^{-2}}\end{array}$

Hence resistance of the metal wire= $3.61 \times 10^{-2}$