Question

A piece of resistance wire of diameter 0.2 M and resistance 0.7 ohms has resistivity of 8.8 × 10-⁴ohms M. Calculate the length of the wire​

Answer 1

Given : R=0.07Ω l=100 cm =1 m d=2 mm =0.002 m

Using R=ρ

(π/4)d

2

l

∴ 0.07=ρ

(π/4)(0.002)

2

1

⟹ ρ=22×10

−6

Ω m