How Fast Do Electrons Drift in an Iron Wire?

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SUMMARY

The drift speed of electrons in a 2.0-mm-diameter iron wire, given a flow of 1.0 * 10^20 electrons in 5.0 seconds, is calculated to be 7.5 * 10^-5 m/s. The relevant equations used include the electron drift speed formula v_d = e*tao/m * E and the total electron equation N_e = n_e * A * v_d * delta(t). The number density of electrons in iron is specified as 8.5 * 10^28 electrons/m^3, and the cross-sectional area A is derived from the wire's radius.

PREREQUISITES
  • Understanding of electron drift speed and its calculation.
  • Familiarity with the concept of electron density in materials.
  • Knowledge of basic geometry for calculating cross-sectional area.
  • Proficiency in manipulating equations involving physical constants and variables.
NEXT STEPS
  • Study the derivation and application of the electron drift speed formula v_d = e*tao/m * E.
  • Explore the concept of electron density and its significance in different materials.
  • Learn about the relationship between current, charge, and drift speed in conductive materials.
  • Investigate the effects of temperature and material properties on electron mobility.
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Students and educators in physics, electrical engineers, and anyone interested in understanding electron behavior in conductive materials.

jheld
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Homework Statement


1.0 * 10^20 electrons flow through a cross section of a 2.0-mm-diameter iron wire in 5.0 s. What is the electron drift speed?


Homework Equations


v_d = e*tao/m * E
i_e = n_e * e * tao * A/m * E


The Attempt at a Solution


I can't seem to get very far. I think that I need to find E, but I'm having no luck actually deriving it.
Any suggestions?
 
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Well I figured it out!

relevant equation:
N_e = n_e * A * v_d * delta(t)
N_e = total electrons in cross-section = 10^20 electrons
n_e = number density of electrons in iron = 8.5*10^28
A = pi*r^2 = pi * (10^-3)^2
delta(t) = 5
so solve for v_d...I get 7.5*10^-5 m/s
 

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