Question

A wire of length 3 m and area of cross-section 1.7 × 10-6 m2 has a resistance 3 × 10-2 ohm.
a. What is the formula for resistivity of the wire and what is the unit of it
b. Calculate the resistivity of the wire​

Answer 1

Answer:

Solution

a. Resistivity of the wire is given by

ρ=R

A

L

And It unit is Ohm-m

b. In this case

L=3 m

A=1.7×10−6 m2

R=3×10−2 ohm

So

ρ=1.7×10−8 Ohm-m

Answer 2

Answer:

Formula

resistivity , ρ = RA/l

Unit

ρ=ohm.meter[S.Iunit]

$resistivity = \frac{1.7\times {10 \times }^{ - 6} \times 3 \times {10}^{ - 2} }{3} = 1.7 \times {10}^{ - 8}$