Question

An aluminium wire has a length 5km and radius 1.4mm.Find the resistance of the aluminum wire(resistivity of aluminium=2.63× 10 to the power minus 8)​

Answer 1

Answer: 21 Ω approx.

Explanation:

We know,

R = ρl/A

Given,

ρ = 2.63 x $10^{-8}$

l = 5km = 5000 m = 5 x $10^{3}$

A = π$r^{2}$

   = $\frac{22}{7}$ x (1.4 x $10^{-3}$)^2

   = 22 x 0.28 x $10^{-6}$ $m^{2}$

Now,

R = $(\frac{2.63 * 10^{-8} * 5 * 10^{3} }{6.16 * 10^{-6} })$ Ω

  = 2.13 x 10

  = 21 Ω approx.

Tell me if I am wrong.

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