Confused about electric field/velocity/magnetic field vectors

In summary, the conversation discusses the relationship between E, v, and B in the presence of an electric and magnetic field. It is stated that E = v cross B, but in a specific scenario with v = 5j and B = -1k, E is in the positive i direction instead of the expected negative direction. It is also mentioned that in the case of an electromagnetic wave, the notation for E should be -v cross B. The conversation also touches on the use of the right hand rule to determine the direction of the force.
  • #1
beanus
17
0
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.
 
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  • #2
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
beanus said:
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
rocketnukem said:
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.
 

What is an electric field vector?

An electric field vector is a mathematical vector that represents the strength and direction of the electric field at any given point in space. It is denoted by the symbol E and is measured in units of volts per meter (V/m).

How is electric field related to electric charge?

Electric field is created by electric charges. A positive charge will create an electric field that points away from it, while a negative charge will create an electric field that points towards it. The strength of the electric field is directly proportional to the magnitude of the charge.

What is the relationship between electric field and velocity?

Electric field and velocity are not directly related. However, the electric field can exert a force on a charged particle, causing it to accelerate and change its velocity.

What is a magnetic field vector?

A magnetic field vector is a mathematical vector that represents the strength and direction of the magnetic field at any given point in space. It is denoted by the symbol B and is measured in units of tesla (T).

How does magnetic field interact with electric field?

Magnetic fields can interact with electric fields through a phenomenon known as electromagnetic induction. When a changing magnetic field passes through a conductor, it induces an electric field, which in turn can induce a current in the conductor.

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