Question

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

Answer 1

length of wire = 1m
diameter of wire = 0.2 mm
radius of wire = 0.1mm = 10^(-3) m = 0.0001 m
resistance of wire = 10 ohms
as
resistivity =
$(resistance)( \frac{area}{length} )$
resistivity = (10)[ π (0.0001)^2 ]/ (1)
resistivity = π(0.0000001)
= π ( 10^(-7) )
= 3.14 x 10^(-7) ohm-metre

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!