#### Question

Calculate the resistance of an aluminium cable of length 10 km and diameter 2.0 mm if the resistivity of aluminium is 27 × 10^{−8} Ωm.

#### Solution

Length of the cable wire,

*l*= 10 km = 10000 mDiameter of the cable wire,

*d*= 2.0 mmRadius of the cable wire,

*r*= 0.1 mm = 0.0001 m = 10^{-4 }mArea of cross-section, `A=Api^2` 3.14 × 10

^{-8}m^{2}Resistivity of the aluminium cable wire = 27 × 10

^{−8}Ω m.Let the resistance of the aluminium cable be *R*.

We know that `R=l/A`

R=P/A

`R=27xx10-8xx103.14xx10-8`

`R=(27xx10^-8xx10000)/(3.14xx10^-8)`

*R* = 86 Ω

Is there an error in this question or solution?

Solution Calculate the Resistance of an Aluminium Cable of Length 10 Km and Diameter 2.0 Mm If the Resistivity of Aluminium is 27 × 10−8 ωM. Concept: Resistance of a System of Resistors - Resistors in Series.