Question regarding Magnetic field

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Homework Help Overview

The problem involves the transformation of electric and magnetic fields between two reference frames in the context of special relativity. The original poster is tasked with identifying incorrect equations related to these transformations.

Discussion Character

  • Conceptual clarification, Assumption checking, Mixed

Approaches and Questions Raised

  • The original poster questions the meaning of 'c' in the equations and expresses confusion about how the magnitude of fields can change with different frames. Some participants suggest that dimensional analysis could be a useful approach to tackle the problem.

Discussion Status

The discussion is exploring the nature of electric and magnetic field transformations, with participants providing insights into the relevance of special relativity and dimensional analysis. There is no explicit consensus on the correct equations yet, but some guidance has been offered regarding the use of dimensional analysis.

Contextual Notes

The original poster indicates a lack of understanding regarding the transformation of fields and the implications of the speed of light in the equations. There may be assumptions about the nature of fields that are being questioned.

utkarshakash
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Homework Statement


Let [itex]\vec{E}[/itex] and [itex]\vec{B}[/itex] denote electric and magnetic fields in a frame S and [itex]\vec{E'}[/itex] and [itex]\vec{B'}[/itex] in another frame S' moving with respect to S at a velocity [itex]\vec{v}[/itex]. Two of the following equations are wrong. Identify them.

a)[itex]B_y ' = B_y + \dfrac{vE_z}{c^2}[/itex]
b)[itex]E_y ' = E_y - \dfrac{vB_z}{c^2}[/itex]
c)[itex]b_y ' = B_y + vE_z[/itex]
d)[itex]E_y ' = E_y + vB_z[/itex]

Homework Equations



The Attempt at a Solution


First of all I can't understand what is 'c' here. Is it speed of light?Also, how can the magnitude of field change with frame? The magnitude of force can vary but I don't think field should vary. This question seems too complicated to me.
 
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##c## is the speed of light yes. The magnetic and electric fields transform non-trivially under Lorentz boosts; one can prove this using special relativity. You can probably look it up online if you don't have a textbook that discusses it.
 
Dimensional analysis might be useful here.
 
jtbell said:
Dimensional analysis might be useful here.

Hmm... So its just basically a problem of dimensional analysis. No magnetics involved.
 

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