Question

A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 ohm calculate the resistivity of its material??

Answer 1

Here , it is Given that:


l=1m ,d=0.2mm=>r=0.1mm and R=10 ohm

by using the formula, 

R= p౹/ A

= p౹/ πr²

therefore, p= Rπr²/l

= 10× 3.14×( 0.1× 10 -³)²

= 10× 3.14× 0.1×0.1× 10 to the power -6

= 0.314× 10 to the power-6

= 3.14× 10 to the power-7 ohm- m 

hence, the resistivity of the conductor is 3.14× 10 to the power-7 ohm- m