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Ohm's Law for moving charge

  1. Apr 5, 2012 #1
    Dear Fellows I have just came across with the basics of electromagnetism, and about the application of electric and magnetic force on charge particle,

    Ohm's law for charge is
    j=σE (1)
    if the charge is moving with the speed "u"
    then, j=σ(E+u[itex]\times[/itex] B) (2)

    force on a charge by electric field is
    F=q.E (3)
    if the charge is moving through the electromagnetic field,
    F=q(E+u[itex]\times[/itex]B) (4)

    I am supposed to use equation of motion for solid particles i.e.,
    σ_ij,j+f_i=ρu'_i (u'=acceleration ' is for time derivative) (5)

    my questions are
    1- How equation (1) is converted to equation (2) if the partical started moving ??
    2- similarly how equation (3) is converted to equation (4)
    3- in final form eq (5) if found f_i = lorantz force but in (5) they use f_i =J[itex]\times[/itex]B, why they did not use equation (4) in this situation.

    thank you for your cooperation
  2. jcsd
  3. Apr 5, 2012 #2
  4. Apr 5, 2012 #3
    Thank You very much for your reply but the information given by the link you have given is not good enough....
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