Question

Una bombilla de incandescencia tiene un filamento de wolframio cuya resistividad es de 5,6 por 10 a la -8 m , su longitud es de 200 cm y su sección es de 8,0 por 10 a la -7 malcuadrado ¿resistencia?

Answer 1

R = 0.14 Ω

Step-by-step explanation:

The resistance of a metal is given by the relation

R =
`\rho (L)/(A)`

where ρ the resistivity is 5.6 10-8 Ω m, they also give the length and the cross section (area)

Let's reduce the magnitudes to the SI system

L = 200cm (1m / 100cm) = 2.00m

A = 8.0 10⁻⁷ m²

let's calculate

R = 5.6 10⁻⁸
`(2.00)/(8.0 \ 10^(-7) )`

R = 1.4 10⁻¹ Ω

R = 0.14 Ω