1. Limited time only! Sign up for a free 30min personal 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!

Stopping Potential Question

  1. Apr 16, 2016 #1
    1. The problem statement, all variables and given/known data

    Electrons are accelerated through a potential V and then they are suddenly stopped and emit photons. Derive the minimal value that the potential should have in order to produce some X-Ray photons of wavelength 10-10m.

    2. Relevant equations
    E=hc/λ
    V=(h/e)(f-f0)

    3. The attempt at a solution
    I used E=hc/λ to find the energy of the X ray photons. I found E= 1.989x10-15 = 12431.25 eV

    Not sure if I needed to do this or what to do next. All help is appreciated. Thank you.
     
  2. jcsd
  3. Apr 16, 2016 #2

    gneill

    User Avatar

    Staff: Mentor

    Hi DarkMatter5, Welcome to Physics Forums!

    You have found the energy, and cleverly expressed it in electron volts. What electric potential difference (Volts) should the electron be accelerated through in order to achieve that energy?

    By the way, you might want to round your result to suit the given significant figures.
     
  4. Apr 16, 2016 #3
    I guess it would be 12431.25 V? And is it to 1 sig fig? so 1 x 104 V?
     
  5. Apr 16, 2016 #4

    gneill

    User Avatar

    Staff: Mentor

    Yup.
     
  6. Apr 16, 2016 #5
    Thank you very much!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Stopping Potential Question
  1. Stopping Potential (Replies: 2)

  2. Stopping Potential (Replies: 1)

Loading...