Question

A wire is 1m long, 0.2mm in diameter and has a resistance of 10ohm. Calculate the resistivity of its material? With full explanation

Answer 1

Solution:

d = 0.2mm = 0.2×10^-3m = 2×10^-4m

=> r = 1×10^-4 m

L = 1m

A = πr²

= 3.14×(1×10^-4)²

= 3.14×10^(-8) m²

R = 10 ohms
resistivity = R×A/L

= 10×3.14×10^(-8)/1

= 3.14×10^(-7) ohm m

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!