Which is the correct Expression for Drift Velocity of Electrons in a conductor ?

In summary, the conversation is about confusion regarding different expressions for drift velocity from multiple sources. One source, MIT Professor Walter Lewin, states that Vd = eE/m x (Tau), while the other source, a book, says Vd = eE/2m x (Tau). The individual is unsure of which expression is correct and is seeking clarification. Additionally, the validity of the second expression is questioned due to the consideration of the time between collisions and the use of instantaneous velocity.
  • #1
nishantve1
76
1
i am really really confused . I know what Drift velocity is but the problem is I have three Sources which tell absolutely different expression for drift velocity and I cat relate . please tell which is right .
This website and MIT Profs. Walter Lewin In his Lectures says Vd = eE/m x (Tau)
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmmic.html

And my book says Vd = eE/2m x (Tau)
Thats Ridiculous Heres the proof
kPo9L.jpg


What the heck is goin on ?
 
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  • #2
Actually the second expression is not fully valid...if you take into consideration the time between two successfull collisions of an electron, then the time will be negligible annd the so called relaxation time will tend to 0. So you can't take average velocity in this case and you are bound to take the instantaneous velocity i.e, v=dl/dt.So the second one is not fully correct...by any case...is this book the second part of H.C.Verma ?
 

1. What is drift velocity?

Drift velocity is the average velocity of electrons moving through a conductor in the presence of an electric field.

2. How is drift velocity related to electric current?

Drift velocity is directly proportional to the electric current in a conductor. This means that as the drift velocity increases, the electric current also increases.

3. What factors affect the drift velocity of electrons in a conductor?

The drift velocity of electrons is affected by the strength of the electric field, the type of material the conductor is made of, and the temperature of the conductor.

4. What is the correct expression for drift velocity of electrons in a conductor?

The correct expression for drift velocity of electrons in a conductor is vd = μE, where vd is the drift velocity, μ is the electron mobility, and E is the electric field strength.

5. How is the drift velocity of electrons different in different types of conductors?

The drift velocity of electrons can vary in different types of conductors due to differences in their material properties, such as electron mobility and resistance. Some materials, such as metals, have a higher electron mobility and therefore a higher drift velocity compared to other materials, such as semiconductors.

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