You will need to first calculate the number density of free conducting electrons. Call it N. It equals the number density of copper atoms. You can get that from the density of copper and the atomic weight.
For the drift velocity V, use the equation
N*e*V*A= 3.2*10^-10 coulombs/second
A is the cross sectional area, pi*D^2/4
A small but measurable current of 3.20 E-10 A. exists in a copper wire whose diameter is 0.03 cm. Calculate the electron drift speed (in meters/second).
3 answers
ive previously tried this and obtained 3.34e-13 m/s which the computer says is wrong
where N = 8.46e28 m^-3
e = 1.6e-19 C
and A = 7.07e-8 m^2
where N = 8.46e28 m^-3
e = 1.6e-19 C
and A = 7.07e-8 m^2
Let's see if I agree with your value of N.
Copper density = 8.92 g/cm^3
Copper atomic weight = 63.5 g/mole
Copper molar density = 0.1405 mole/cm^3
= 1.405*10^5 moles/m^3
= 8.456*10^28 atom/m^3
That equals the free electron number density, N
A = (pi/4)*(3*10^-4 m)^2 = 7.06*10^-8 m^2
V = 3.35*10^-13 m/s
I agree with your number.
Copper density = 8.92 g/cm^3
Copper atomic weight = 63.5 g/mole
Copper molar density = 0.1405 mole/cm^3
= 1.405*10^5 moles/m^3
= 8.456*10^28 atom/m^3
That equals the free electron number density, N
A = (pi/4)*(3*10^-4 m)^2 = 7.06*10^-8 m^2
V = 3.35*10^-13 m/s
I agree with your number.
0 answers