3B w v/R...
This is a classical question of magnetic flux...
The bluish part is a metalic conductor which is moving with a velocity v
There is a magnetic field in the dotted circular region...
will there be the current in the loop? If yes what will the value be? if No why?
Extra data:
radius of the loop is r, width of slab is w and the area common to both the slab and the magnetic field is A.THe resitatnce of wire is R
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28 Answers
62There will be current flow.. but can someone explain this whole phenomenon in terms of the electrons..? ?
This is pretty basic and i wud rate important for the understanding EMI!
24Looks like I have to write derivation of motional emf to justify myself
are u satisfied now ???
3if the conductor is in 2d the motion will be restricted na,dats y first i said that no current flows,sir is this like a 3d slab.
3since the motion of the electrons were random so i think we cant get net electric field.Also here induced electric field is zero since we have a constant flux.
24Sir the current will surely be produced by electric field..if Virangs answer has been accepted it means that motional emf is produced...and the basis of motional emf is
that particles inside rod/slab experience lorentz force =>accelrate in rod
=>polarization of particles in rod/slab
=> Electric field created within the rod/slab...
11no sir but i thought... it is wrong since u did not say anything about it
62eureka.. here the current is not produced due to the electric field.. but due to the force on a moving electron in a magnetic field...
24sir this is what I told u yesterday in ur chatbox....
i told u taht current will be produced when there is electric field ..
1the electrons in the slab will go in downward direction due to the force acting on them
so the slab will behave as a cell with the upper plate as the positive one
current will be w v B / r
nishant bhaiyya is this rite????
3sir i think no bcos the area enclosed by the magnetic field and the conductor is not changing so no change in flux.
1well I dint know there was this condition for motional emf to be generated
is there ?
24@philip how will emf be genrated in first case ??
motion of loop is parallel to its length in first case...so no motional emf
1no EMF is definitely generated in the first situation also
1) in eqb (in absence of conducting loop)
evB = eE (E = conservative induced electice field)
2) Emf = E.w = Bvw
i think the only problem is in step (1) here (whether that situation is reached or how)
24jsut a qualitative reply
i know all would be knowing this..so plz dont thrash me :P
1as the slab moves towards right the electrons inside experience a force
q v X B
therefore one side will be at a higher potential than the other
but something is wrong .since B is not given...[12]
11yes the flux is not changing but we do know that if we move a conductor in a magnetic field there will be a induced emf. And that emf is induced in this case
62@virang.. but the magnetic flux through the circle is not changing!! what is the justification of what you have done?
11There will be current
E = Bvw
I= E/R
I = Bvw/R
where B is the magnetic field
62It is a slab.. and it will matter a bit .. but not too much.. (the calculations will change.. but the concept being used will not)
24is it a slab or loop ???
i dont know whether it will help me or not in solving hte question.but just asking ..