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!

Field lines image

  1. Aug 27, 2009 #1
    Like a radioactive particle emit rays, does this similar to the field lines of a charged particle?
    at what speed these field lines are generated from the charge particle??????
  2. jcsd
  3. Aug 27, 2009 #2


    User Avatar
    Science Advisor

    What kind of rays are you talking about? Gamma rays, for example, are a form of electro-magnetic radiation, just as light is and behave exactly like light (with very, very high frequency). Alpha rays, on the other hand, are rays of alpha particles, consisting of two protons and two neutrons, so are charge and act exactly like charged particles! Beta particles are high speed electrons or protons, so again, charged particles.
  4. Aug 27, 2009 #3
    here i'm not talking about any particular ray, matter is about the field line velocity of a charged particle, as rays are of different frequency or velocity like this, does field lines generated from charged particle have any frequency or something like energy???????
    hope u understand now my Q????
  5. Aug 27, 2009 #4
    field lines are pedagogical constructs to help in instructions ... they are not real dear. do not worry none of the field lines will fly at high speed out of the electrons and hit you ... relax !
  6. Aug 27, 2009 #5
    if it is for instruction then why flux density is proportional to the density of lines.i mean there is not any criteria for making no. of lines passing through a small area.
    it must have some reality to make sense!!!!
    Last edited: Aug 27, 2009
  7. Aug 27, 2009 #6


    Staff: Mentor

    It is just a graphing tool. You simply draw the lines so that the number of lines passing through a small area is proportional to the flux density.
  8. Aug 27, 2009 #7
    suppose it is real and you take a small enough cross section which avoids all the lines (as the no of lines is finite you can always do this) .. does that mean there is no electro-magnetic field inside that cross section ... what if you take that cross section really near the electron .. does it not sound absurd to you that there are numerous small cross sections very near the electron which does not register any electric field ?

    what DaleSpam is saying is correct ... one draws the lines after they have computed the flux just to show everything in a decent way to high school students like you. to make the diagrams realistic one draws the number of lines to be proportional to the cross section.
  9. Aug 27, 2009 #8
    it may be. but without any criteria how we can just draw these lines, because flux density is constant for any charged particle unless it interupted by any other particle. so flux density is not depends on no. of lines that you draw. i think no. of lines is infinite for any charged particle/
  10. Aug 27, 2009 #9


    Staff: Mentor

    I don't understand what you are trying to say here. Flux density for a charged particle is not constant, it falls off as 1/r². Again, it is useless to try to think of the lines as something real, they are a visualization tool, nothing more.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook