Understanding the Effects of Electric and Magnetic Fields on Moving Charges

[adnan jahan]

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$\times$ 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$\times$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 particle 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$\times$B, why they did not use equation (4) in this situation.


thank you for your cooperation

 

[Dreamer78692]

Here is something that could help you:

http://www.physicsforidiots.com/em.html

 

[adnan jahan]

Thank You very much for your reply but the information given by the link you have given is not good enough...