sir,

imagine a situation when we are standing in an elevator,a uniform magnetic field is existing horizontaly say-from west to east.electron is thrown upwards with a velocity "v" in the mid air(outside the elevator) with the help of an electron gun.at that same instant i start the elevator with the same speed "v".initially the electron would be in rest with respect to me,thus no magnetic force should be experienced by the electron in my frame,but still the electron seems to be deflecting from its path why???? do we observe a transformation of magnetic field to electric field in this elevator frame??

in a non-relativistic approx. the Lorentz force does not depend on the choice of the intertial reference frame

F=qE+q(v x B)    the formula is vectorially written

in the frame of the elevator the u r having some vel and the electron is also having some vel so acc to Lorentz expresiion the value of v has changed but the correcponding value of E has also changed in ur frame keeping the net force constant.

actually there is  division  of the force into electrical and magnetic comp.

so i think that there is the transformation of magnetic force into electrostatic force !!!!

tell me if i m correct?

@kaymant sir this was when we were talking in a non-relativistic regime now my doubt is that will the ans change when we are in a relativistic regime

I dont think the there would be any change as charge remains constant in a relativistic regime unlike mass.

plz comment.

@islahul_101 it was a good question u compelled me think higher so i m rating u

hey check out hc verma theory in magntic feild and then go for short answer question.

@animal:

The Lorentz force does changes if you change you reference frame. The reason is the presence of the velocity in the Lorentz formula. In fact, in any formula where the velocity is present you should be a bit cautious, because by changing the reference frame the velocity will change.

As far as the non-relativistic approach is concerned, it turns out that given electrostatics and relativity you can explain all phenomena without using magnestism, that is magnetism becomes redundant then -- it becomes just a word in the dictionry!

For example, suppose there is straight wire (which we think of two lines having equal positive and negative charges) that carries a steady direct current. Then, we can think of the electrons moving with a drift speed v in a direction opposite that of the current while the positive charges sit at the lattice points. If a charged particle is projected with a speed u, then in the laboratory frame, the charge will experience a ''magnetic'' force according to Lorentz force law (note that there won't be any electric force because the net charge on the wire is zero).

Now imagine another reference frame in which the charged particle is at rest. Then there wont's be a magnetic force (since the velocity is zero). But in this reference frame, the positive and negative line of charge will suffer different (relativistic) contraction due to which the net charge now per unit length of the wire is not zero and this excess charge will exert an electric force on our point charge. It can be shown by calculations that the force measured in the two frames are exactly the same. 

this means that the Lorentz force remains contant which i have also written in a relativistic regime which means that i m correct

thanx for u r comment