Confused about electric field/velocity/magnetic field vectors

  • Thread starter beanus
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  • #1
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Main Question or Discussion Point

So E=vB and {E}={v}cross{B} but if I have for instance v=5j and B=-1k, then E is in the positive i direction. Shouldn't it be in the negative direction? Thanks.
 

Answers and Replies

  • #2
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Unless, I'm missing something, it's not true that E = v cross B.

It's F = qv cross B if there is no electric field or F = q(E + v cross B) if there is an electric field.

Unless you want to say that there is an electric field there that is exactly canceling the magnetic force. Then F = 0, and you get E = -v cross B. But that's a very specific situation.
 
  • #3
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So E=vB and {E}={v}cross{B} but if I have for instance v=5j and B=-1k, then E is in the positive i direction. Shouldn't it be in the negative direction? Thanks.
Are you talking about an electromagnetic wave?
If this is the case, I think it is {E}=-{v}cross{B}, in the usual notations.
 
  • #4
Yes, F=qvXb or F=qvbsin(thata). Try using the right hand rule.

1.) point hand in the direction of v
2.) curl fingers in the direction of B
3.) thumb points in the direction of the force
 
  • #5
3,732
414
Yes, F=qvXb or F=qvbsin(thata). Try using the right hand rule.

1.) point hand in the direction of v
2.) curl fingers in the direction of B
3.) thumb points in the direction of the force
I don't think this has much to do with the OP.
 
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