Question

What is the resistance of 1.0 m of no. 18 copper wire (diameter 0.40 in)? (The resistivity of

copper is 1.68 × 10-8 .m.)​

Answer 1

Answer:

2.514×10

−7

Ωm

Explanation:

Given : R=2Ω l=1 m d=0.4 mm =0.0004 m

Cross section area of wire A=

4

πd

2

=

4

π×(0.0004)

2

=1.256×10

−7

m

2

Resistivity of the material ρ=

l

RA

∴ ρ=

1

2×1.256×10

−7

=2.514×10

−7

Ωm