Question

A tungsten wire is 4.5 m long and 0.55 mm in diameter. what is its resistance?

Answer 1

First you need to know the formula for resistance, which is:


`R=` ρ
`(L)/(A)` --- (A)

Where,
ρ = Resistivity
L = length
A = Area

ρ = Resistivity of tungsten = 5.28 x
`10^(-8)` Ωm
L = Length = 4.5 m
A = Area = 0.55 *
`10^(-3)` * π

Plug-in the values in equation(A), you would get:


`Resistance = (5.28 *10^(-8) * 4.5)/(0.55 * 10^(-3) * \pi )`


`Resistance = 1.375 * 10^(-4)`Ω