Question

A wire is 1m long ,0.2mm in diameter and has resistance of 10 ohm.calculate its resistivity

Answer 1

As we know that,

R =¶ L/A

where ¶ is resistivity

A is πr^2
Here d is 0.2 mm then r will be 0.1 mm which is equal to 0.001m.
l is 1m
R is 10 ohm

¶ = RA/l

Substitute values of R,A and l to calculate resistivity.

Hope you get your answer.

Answer 2

Hey there!

Given,

Length(l) = 1 m

Diameter(d) = 0.2 mm

Radius(r) = 0.1 mm or 0.001 m

Resistance(R) = 10 Ω

Now,

 Area =πr²

         = 3.14 × 0.001 × 0.001

         = 0.00000314 m²

We know,

Resistivity = RA/l

                = 10 × 0.00000314/1

                = 0.0000314 Ω m

                = 3.14×10^-7 Ω m

Hope It Helps You!