Calculate Total Collisions of Free Electrons in Extension Cord

  • Thread starter Thread starter fubag
  • Start date Start date
  • Tags Tags
    Wire
Click For Summary
SUMMARY

The discussion focuses on calculating the total number of collisions (N_c) of free electrons in a copper extension cord with a current of 8.0 A, length of 3.00 m, and diameter of 1.5 mm. The resistivity of copper is 1.7 x 10-8 Ω·m, and the concentration of free electrons is 8.5 x 1028 m-3. The drift velocity is given as 3.3 x 10-4 m/s. Participants express difficulty in determining the electric field necessary to calculate the acceleration of electrons, which is essential for finding the time between collisions (τ).

PREREQUISITES
  • Copper resistivity (1.7 x 10-8 Ω·m)
  • Drift velocity calculation (3.3 x 10-4 m/s)
  • Understanding of electron charge (1.6 x 10-19 C)
  • Concept of free electron concentration (8.5 x 1028 m-3)
NEXT STEPS
  • Calculate the electric field (E) in the extension cord using Ohm's law.
  • Determine the acceleration (a) of electrons using the formula a = eE/M_e.
  • Find the time between collisions (τ) using the relationship V_d = aτ.
  • Calculate the total number of collisions (N_c) using N_c = n * V_d * τ.
USEFUL FOR

Students and professionals in electrical engineering, physics enthusiasts, and anyone interested in understanding electron behavior in conductive materials.

fubag
Messages
105
Reaction score
0
A current of I=8.0\;\rm A is flowing in a typical extension cord of length L=3.00 m. The cord is made of copper wire with diameter d=1.5mm.

The charge of the electron is e=1.6 *10^{-19} C. The resistivity of copper is \rho=1.7 *10^{-8}\; Omega*m. The concentration of free electrons in copper is n=8.5 *10^{28}\;m^{-3}.

Find the total number of collisions ( N_c) that all free electrons in this extension cord undergo in one second.

I know Velocity(drift) = 3.3 * 10^-4 m/s.

I tried to relate the formula V_d = a*Tau, to find Tau the time between collisions...

However given the information I was stuck solving for a = eE/M_e, because I could not determine the electric field...

Can someone please assist me on what information I might be missing?
 
Physics news on Phys.org
anyone?
 
im still stuck on this question...
 
ok so since no one seems to have a clue about this problem...

any suggestions of where I may be able to find the answer?
 

Similar threads

Find the drift speed of electrons in a wire
  • · Replies 2 ·
Replies
2
Views
2K
Calculating Collision Frequency of Electrons in Copper Cube
  • · Replies 2 ·
Replies
2
Views
2K
How Does Current Flow Through a Copper Wire?
  • · Replies 3 ·
Replies
3
Views
11K
How Fast Do Electrons Travel in a Copper Wire?
  • · Replies 4 ·
Replies
4
Views
6K
E-Field Through Copper Wire given drift velocity
  • · Replies 2 ·
Replies
2
Views
8K
Find Electron Current Through Iron Wire
  • · Replies 1 ·
Replies
1
Views
11K
How Long Does It Take an Electron to Travel Through a Copper Wire?
  • · Replies 1 ·
Replies
1
Views
2K
Find Drift Speed of Electrons in Copper Wire | Tom
  • · Replies 2 ·
Replies
2
Views
2K
Electron's Velocity: Calculating w/ Gauss' Thm
  • · Replies 28 ·
Replies
28
Views
2K
Extension cord connected to heater - Find the power
  • · Replies 4 ·
Replies
4
Views
5K