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skatetony Mar 6th 2013 07:52 AM

Motional EMF related question
 
A metallic rod is held horizontally along east-west direction, is allowed to fall under gravity. Will there be an EMF induced at its ends? Justify your answer.

My answer - The magnetic field of Earth is constant and hence there is no magnetic flux change and hence no EMF.

Friend's answer - The free electrons on the rod experience a force due to magn. field given by F=qvXB
Hence electrons move to one side and EMF is induced.

Please tell me which answer is correct.

DrPhil Mar 6th 2013 03:20 PM

Quote:

Originally Posted by skatetony (Post 19819)
A metallic rod is held horizontally along east-west direction, is allowed to fall under gravity. Will there be an EMF induced at its ends? Justify your answer.

My answer - The magnetic field of Earth is constant and hence there is no magnetic flux change and hence no EMF.

Friend's answer - The free electrons on the rod experience a force due to magn. field given by F=qvXB
Hence electrons move to one side and EMF is induced.

Please tell me which answer is correct.

Your friend. Moving a conductor perpendicular to a field is equivalent to moving a field with respect to a conductor.


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