Question

calculate the resistance of an aluminium cable of length 10 km and diameter 2.0mm if the resistivity of aluminium is 2.7×10^-8 ohum m?❤❤❤❤❤​

Answer 1

length, l = 10km =10^4m

diameter , d = 2mm

radius , r = 1mm = 1×10^-3m

resistivity , p= 2.7×10^-8 ohm m

...............

R = pl/A

= pl/πr^2

......................

(2.7×10^-8)×(10^4) _____________________

(22/7)×(1×10^-3)^2

⬇️

(2.7 ×10^-4)

______________ ➡️85.9 ohm

(3.14 ×10^-6)