Question

Can somebody help me out !!!!
Question goes like this,,
Resistance of a metal wire of length 1 m is 26Ω at 20 C. If the diameter of the wire is 0.3 mm, what will be the resistivity of the metal at that temperature?​

Answer 1

Answer:

1.84×10−6Ωm

Explanation:

Given:  R=26 Ω, l=1m, d=0.3mm

Step 1: Resistivity of the metal (ρ)

We know that resistance can be given as :

R=Aρ l

⇒ρ=lR A                 ....(1)

Step 2: Calculations and Substituting the values 

A=4πd2=3.14×4(0.3×10−3m)2=0.071×10−6m2

From equation (1)

 ρ=1 m26 Ω×0.071×10−6 m2=1.84×10−6Ωm