Let us consider a rectangular plate moving horizontally in a vertical magnetic field with its length perpendicular to its direction of motion.This may be closely approximated by the wing of a flying aircraft.The axial emf is given by the traditional formula, E=BLV.(adsbygoogle = window.adsbygoogle || []).push({});

Now when the "axial emf" is being developed a transient current flows from one end to the other along the length of the conductor.The external field should deflect this current and the edges should get charged.Therefore apart from the axial emf(=BLV) we must have a "Transverse Emf" between the edges.

Let us now connect the tips(ie the ends) of the conductor by a wire that is magnetically shielded.Current now continuously flow along the length of the conductor and the connecting wire due to the action of the axial emf=BLV. This current gets continually deflected by the vertical magnetic field.The situation simply represents the Hall Effect,of course in a moving conductor[assume the velocity to be constant]. So we should have a typical Hall Voltage between the edges.

I have tried to deduce an alternative expression for the Hall voltage in relation to moving conductors and you will find it in the uploaded presentation.The presentation is based on the article "On Motional Emf".

Link:http://www.eurojournals.com/ejsr_39_1_11.pdf [Broken]

There is an interesting issue connected with the traditional axial emf.If observation is made from the moving conductor itself the value of the Lorentz force =0[since v=0].So how does the electron move from one end to the other of the conductor.It is of course due to the effect of relativistic transformations. The moving conductor experiences an electric force which is axial and this drives the electron to the other end of the conductor. This matter has been discussed in the article as well as in the uploaded presentation.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# The Axial and the Transverse Emf

**Physics Forums | Science Articles, Homework Help, Discussion**