Question

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

Answer 1

given l=1m     diameter=0.2mm    so radius  r=0.1=0.1*10^-3m   R=10Ω
the formula is R=ρl/A   or ρ=RA/l
ρ=10*22/7 *(0.1*10^-3)^2/1
ρ=220*10^-8
so the resistivity ρ=2.2??*10^-6Ωm

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!