contestada

2. The electrical resistance R of a wire varies inversely with the square of its diameter d. If a wire with a

diameter of 3 millimeters has a resistance of 0.4 ohm, find the resistance of a wire having the same

length and a diameter of 8 millimeters.

Respuesta :

Paounn

Answer:

[tex]0.225 \Omega =225 m\Omega[/tex]

Step-by-step explanation:

We know (Ohm second law) that [tex]R= \frac{k}{d^2}[/tex] where k inlcudes the rest of the parameters (material, lenght). In our situation we have k= [tex]0.4\cdot9 \Omega mm^2[/tex]. The moment the diameter becomes 8mm R becomes

[tex]R= {{0.4\cdot 9}\over{16}} \Omega = 0.225 \Omega[/tex]