Question

1. Calculate the length of aluminium wire of area of
cross-section 1 mm2 whose resistance is 1.56x10 to the power-2
ohm, Given, resistivity of aluminium is 2.6 x 10 to the power-8
ohm-m.​

Answer 1

We know that

R = ρl/a

Where R = resistance,

ρ = resistivity

l = length of the conductor

a = area of cross section.

Given R = 1.56 * 10⁻² ohm

          ρ = 2.6 * 10⁻⁸ ohm/m

          a = 1 mm² = 10⁻⁶ m²

Therefore

1.56 * 10⁻² = l * (2.6 * 10⁻⁸)/10⁻⁶

l = 1.56/2.6

l = 156/260

l = 0.6 m

The length of aluminium wire is 0.6 m.

Answer 2

Answer:

We know that

R = ρl/a

Where R = resistance,

ρ = resistivity

l = length of the conductor

a = area of cross section.

Given R = 1.56 * 10⁻² ohm

         ρ = 2.6 * 10⁻⁸ ohm/m

         a = 1 mm² = 10⁻⁶ m²

Therefore

1.56 * 10⁻² = l * (2.6 * 10⁻⁸)/10⁻⁶

l = 1.56/2.6

l = 156/260

l = 0.6 m

The length of aluminium wire is 0.6 m.