Magnetic Moment, Electron Spin, Energy

Click For Summary
The discussion centers on calculating the potential energy difference between the two orientations of an electron's spin in a magnetic field, using the formula U = -u dot B. The user recognizes that electrons possess up and down spin states and considers using the gyromagnetic ratio g = 2 for calculations. They express confusion regarding the appropriate value for angular momentum, specifically Jz, as the problem does not define quantum numbers n and l. The suggestion is made to utilize the electron spin, S_z, to resolve the issue. Clarification on angular momentum in the context of electron spin is needed for further progress in the solution.
roeb
Messages
98
Reaction score
1

Homework Statement



The PE of a magnetic moment in an external magnetic field is given by U = -u dot B. Calculate the difference in energy between the two possible orientations of an electron in a magnetic field B = .6k T

Homework Equations





The Attempt at a Solution



I realize electrons can have an up spin and down spin, but I am having a hard time doing this problem.

I believe I should be using g = 2 for the gyromagnetic ratio. So: (_h = h bar)
uz = -g uB JZ/_h
uB = e(_h)/(2me)

Unfortunately then I don't know what I should have for Jz. (This is defined by my book as "any type of angular momentum).

So I guess my problem is that I don't know what I should use for angular momentum, since n and l aren't defined in the problem. Can anyone help clear this up?
 
Physics news on Phys.org
Use the electron spin, S_z. Strange you would know about the gyromagnetic ratio but not about which angular momentum that refers to in the case of an electron!
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 19 ·
Replies
19
Views
2K
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 0 ·
Replies
0
Views
830
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K