1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Zeeman effect exercise

  1. Nov 6, 2011 #1

    fluidistic

    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    The [itex]\alpha[/itex] lines of Paschen in the hydrogen spectrum are due to transitions [itex]n=4 \to n=3[/itex]. Identify the allowed [itex]4p \to 3d[/itex] transitions and determine the change in wavelength for each transition if there's an external B field of 2T.


    2. Relevant equations
    [itex]\Delta E=m_l \mu _B B[/itex].
    [itex]E=\frac{hc}{\lambda}[/itex].

    3. The attempt at a solution
    I graphed all transitions possible (it's an enormous mess).
    Now say I want to calculate the difference of wavelength of with and without the magnetic field for the transition 4p, m=0 and 3d, m=1 (it's allowed). I have that [itex]m_l=1[/itex].
    So applying the first formula I gave, this gives [itex]\Delta E \approx 1.85 \times 10^{-23}J=1.16\times 10^{-4}eV[/itex].
    Applying the second formula this gives me [itex]\Delta \lambda \approx 0.01 m[/itex].
    I know this result is totally senseless. It's way too big, enormous. From memory Paschen lines are in the near infrared so about 800 nm and a bit up. Nothing like 0.01m!
    I really don't know what I'm doing wrong.
    I would appreciate some help.
     
  2. jcsd
  3. Nov 9, 2011 #2

    fluidistic

    User Avatar
    Gold Member

    Nevermind, the approach is right. I just made a calculator mistake with the product "hc".
     
  4. Nov 10, 2011 #3

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Hi! Glad it worked out.

    By the way, both eV energy units and the product hc comes up so frequently in quantum mechanics that it's a good idea to remember (or right down, wherever you have a list of physics constants) it's value:

    hc = 1240. eV-nm​

    The energy-wavelength conversions will go quicker that way.
     
  5. Nov 10, 2011 #4

    fluidistic

    User Avatar
    Gold Member

    Thank you for your concern. And yes, I agree with you, I'll get "hc" in eV*nm into my formula sheet.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Zeeman effect exercise
  1. Zeeman effect (Replies: 4)

  2. Zeeman Effect (Replies: 1)

  3. Zeeman effect problem (Replies: 3)

  4. Zeeman Effect (Replies: 18)

  5. Zeeman Effect Lab (Replies: 1)

Loading...