Question

Resistance of a metal wire of length 1meter in 20ohm . if diameter of wire is 0.2mm what will be resistivity of metal at that temperature ​

Answer 1

Answer:

6.28 x 10-⁷ ohm-m

Explanation:

Resistance(R)= 20 ohm

Length (L)= 1m

Diameter= 0.2mm

hence, radius= 0.1 mm= 0.1 x 10-³ m

Area(A)= πr² = 3.14 x 0.1x 0.1 x (10-³)²= 3.14 x 10^-2-6

=3.14 x 10-⁸ m²

R= pL/A

hence, p= RA/L

p= 20 x 3.14 x 10-⁸/1

p= 6.28 x 10-⁷ ohm-m