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Homework Help: 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
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