- #1
sparkle123
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Why is eqn 34.16
B(x,t)•l - B(x+dx,t)•l instead of
B(x+dx,t)•l - B(x,t)•l ?
Thanks!
Why is B(x,t)•l - B(x+dx,t)•l in Maxwell's Eqn 34.16?
- Thread starter sparkle123
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- Maxwell's equations
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Homework Help Overview
The discussion revolves around a specific equation from Maxwell's equations, focusing on the expression B(x,t)•l - B(x+dx,t)•l. Participants are exploring the reasoning behind the order of terms in this equation.
Discussion Character
- Conceptual clarification, Assumption checking
Approaches and Questions Raised
- Participants are questioning the choice of terms in the equation, particularly why B(x,t) is subtracted from B(x+dx,t) rather than the other way around. There is a mention of line integration and the direction of integration in relation to the magnetic field.
Discussion Status
Some participants have provided insights regarding the conventions used in the equation, including references to the right-hand rule and the direction of integration. However, there is no explicit consensus on the reasoning yet, as the discussion is still unfolding.
Contextual Notes
The discussion includes references to conventions in physics, such as the right-hand rule, which may imply assumptions about the orientation of the magnetic field and the integration path.
Why is eqn 34.16
B(x,t)•l - B(x+dx,t)•l instead of
B(x+dx,t)•l - B(x,t)•l ?
Thanks!
- #2
dynamicsolo
Homework Helper
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The line integration is being followed around the rectangle counter-clockwise, so the segment along which the magnetic field is B is parallel to the direction of integration, while the segment with ( B + dB ) is anti-parallel to the integration direction.
- #3
I like Serena
Science Advisor
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MHB
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Hi again sparkle123! 
It's a matter of convention: one of the many applications of the right hand rule.
Point your thumb in the direction of the positive y-axis, and your fingers give the direction that is by convention positive.
This is shown by the arrowheads in the loop.
So B(x,t) is taken as positive, while B(x+dx,t) is taken as negative.
Edit: overtaken by dynamicsolo. ;)
It's a matter of convention: one of the many applications of the right hand rule.
Point your thumb in the direction of the positive y-axis, and your fingers give the direction that is by convention positive.
This is shown by the arrowheads in the loop.
So B(x,t) is taken as positive, while B(x+dx,t) is taken as negative.
Edit: overtaken by dynamicsolo. ;)
- #4
sparkle123
- 172
- 0
Thanks dynamicsolo and I like Serena! :)
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