0
$\begingroup$

I'm dealing with a problem here. Today my professor asked us a question :

How should a metallic wire move in Earth's magnetic field such that she gets maximum potential difference in it's ends:

a) Horizontally b) Vertically c) Normal in the magnetic field lines

Can anyone help me with this question?

Thank you !

$\endgroup$
  • $\begingroup$ A conducting wire, surely? What have you tried? $\endgroup$ – rob May 5 '14 at 20:05
  • $\begingroup$ Oh sorry. Now I corrected the question. Well I think it's option c but I'm not quite shure. $\endgroup$ – Student May 5 '14 at 20:07
  • $\begingroup$ Why do you think so? Why are you not sure? Show us what you have tried. $\endgroup$ – rob May 5 '14 at 20:08
  • $\begingroup$ I thought so because I think when the wire moves normal she hits a big number of magnetic field lines(the maximum that she can hit). $\endgroup$ – Student May 5 '14 at 20:15
1
$\begingroup$

This question is pretty easily solved with an application of the Right Hand Rule. If your thumb points in the direction of motion, and your index finger points in the direction of the magnetic field, then the other finger point in the direction of the force.

So, the magnetic field of the earth goes (roughly) in the north-south direction. You would want the wire to move in a direction perpendicular to the field lines to maximize the effect from the field. Additionally, you'd want the electrons to be at one end of the wire, at a maximum distance away from the other end. So the wire would lay along your "force" direction finger.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.