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?

  R = 0.14  Ω

Explanation:

The resistance of a metal is given by the relation

         R =

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  

       R = 1.4 10⁻¹ Ω

       R = 0.14  Ω

f is prop to m1xm2 double m1 double force

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2