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Faraday's Law

  • Thread starter sara_87
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  • #1
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Homework Statement


An eager student cycles to college at 12 m/s. The metal handle bars are 60 cm wide and cut through the vertical component of the Earth’s magnetic field that has a flux density of 50 *10^(-6) T. Calculate the e.m.f induced across the handlebars. Explain why no current would flow through the student when he touched the metal parts of the handlebars even if he were a good electrical conductor.



The Attempt at a Solution


i can find the e.m.f:

e.m.f= -3.6 * 10^(-4)

but i can't explain why ...i think it has something to do with F=BIL


any help would be much appreciated
 

Answers and Replies

  • #2
Dick
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It is indeed because there is no changing flux through the loop of student+handlebars. But you can also ask yourself what e.m.f. is induced across the hands of the student.
 
  • #3
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the emf that i calculated in the first part of the question?
 
  • #4
Dick
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Yes, the student has the same e.m.f. as the handlebars. Does any current flow?
 
  • #5
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i don't get it, i don't see how any of this is linked
 
  • #6
Dick
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If you have two batteries with equal voltage and you connect their positive terminals together and the negative terminals together, how much current flows in the loop? It's the same problem.
 
  • #7
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is it zero current?
 
  • #8
Dick
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Yes. There's no e.m.f. difference between the two positive terminals or the two negative terminals. Do you see why your problem is the same?
 
  • #9
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it's because the student and the handle bars have the same e.m.f....?
 
  • #10
Dick
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Yes again.
 
  • #11
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Oh thanx alot i get it all now
 
Last edited:

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