In: Physics
8.0 x 10^15 electrons flow through a cross section of silver wire in 340 us with a drift speed of 7.6 x 10^-4m/s .
What is the diameter of the wire?
The number of electrons can be expressed as,
Ne = nAvt
Thus, the area of the cross-section of wire is,
A = Ne / nvt
(pi)r2 = Ne /nvt
Thus, the radius of the wire is,
r = [Ne/ (pi)nvt)]1/2
= [(8.0 x 10^15) / (pi)(5.8x1028 m^-3)(7.6 x 10^-4 m/s)(340x10-6 s)]1/2
= 4.122x10-4 m
Therefore, the diameter of the wire is,
d = 2r
= 2(4.122x10-4 m)
= 8.244x10-4 m
= 0.8244 mm