An iron wire has length 8.0m and a diameter 0.50mm. The sir has a resistance R.

A second iron wire has length 2.0m and diameter 1.0mm

What is the resistance of the second wire?

Respuesta :

The resistance of the second wire is 16 R.
where R is the resistance of the first wire.

R = 
ρ[tex] \frac{l}{A} [/tex]
where l = length of the wire
A = area of the wire
A = [tex] \pi r^{2} [/tex] where, r = [tex] \frac{diameter of wire}{2} [/tex]

Thus, on finding the ratio of resistance of the two wires, we get,

[tex] \frac{R1}{R2} = \frac{l1A2}{l2A1} [/tex]

here, R1 = R
l1 = 8m
l2 = 2m
A1=π[tex] 0.25^{2} [/tex]
A1=π[tex] 0.50^{2} [/tex]

we get. R2 = 16R