1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Electron in a Magnetic field

  1. Apr 16, 2010 #1
    Hello I do not understand one of the problems in my SAT Physics book.
    1. The problem statement, all variables and given/known data

    The subsequent path of the electron is...
    the answer for this given by the book is : Spiral or Helix
    (It does not exist any picture in the book to this question.)

    The explanation the book gives for this answer is:
    The electron will orbit a magnetic field line but will also continue to move towards the bottom of the page , spiraling downwards.

    My question for this is Why is it moving that way? There is no explanation given.

    This question is out of the SAT Subject Test: Physics from Kaplan.

    It would be nice to get an answer soon.
    I am studying SAT Physics in a Club, so we all have got the same problem with this.
    Last edited: Apr 16, 2010
  2. jcsd
  3. Apr 16, 2010 #2
    Ah okay I figured out half of it... there was a picture...
    The force applied on the proton is according to the Right hand rule into the page.

    So the question left is only: why does a charged particle moves in a spiral into the page and not in a line (of course not in the beginning but after the direction changed).
  4. Apr 17, 2010 #3
    We figured out the answer so there is no reply needed anymore
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook