Question

A wire is 1.0 m long , 0.2mm in diameter , and has a resistor of 10Ω.
Calculate the resistivity of the material ?

Answer 1

R=¶l/ a
Given, R= 10 l=0.1 d=0.2mm..r=0.1mm
a=πr^2
=22/7 × 1/10× 1/10
=22/700

10 = ¶ × 1/10
_______
22/700

¶ = 10 × 22/700
________
1/1O

= 10 × 10 × 22
__________
700

= 22/7 =π = 3.14

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!