Understanding the Left-Hand Rule in Electrodynamics

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    Electrodynamics
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Discussion Overview

The discussion revolves around the left-hand rule in electrodynamics, specifically its application in predicting the motion of a current-carrying wire in a magnetic field. Participants explore both the rule itself and its mathematical representation.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant explains Fleming's left-hand rule, detailing how to use it to determine the direction of force on a wire in a magnetic field.
  • Another participant introduces a mathematical expression for the force on the wire, emphasizing the importance of the cross product in the context of the left-hand rule.
  • A later reply suggests a correction to the mathematical expression provided, indicating a potential misunderstanding or differing interpretation of the notation.
  • There is a humorous remark about the potential consequences of forgetting the cross product, highlighting the importance of precision in applying the rule.

Areas of Agreement / Disagreement

Participants present differing views on the explanation and application of the left-hand rule, with some focusing on the rule itself and others emphasizing the mathematical formulation. No consensus is reached regarding the preferred approach or notation.

Contextual Notes

The discussion includes varying interpretations of the mathematical representation of the left-hand rule, which may depend on specific definitions or contexts. There is also an acknowledgment of potential misunderstandings related to the application of the rule.

Reshma
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Can someone explain me the left-hand rule in Electrodynamics?
 
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Reshma,

the left hand rule, known as Fleming's left hand rule, is used to predict the motion of a wire carrying current when the wire is placed in a magnetic field. As you know, the current in the wire will induce a magnetic field and that magnetic field will react with the magnetic field of the magnet. the left hand rule helps you predict the movement of the wire.

Point your thumb straight out, and use your first finger to point in the direction of the magnetic field, and your second finger in the direction of the current. Your thumb will be pointing in the direction of the force experienced by the wire.

visit www.le.ac.uk/se/centres/sci/selfstudy/mam12.htm for a visual illustration (reference)
 
Reshma said:
Can someone explain me the left-hand rule in Electrodynamics?

Yes,how about aplying the definition?

[tex]\vec{F_{em}}=I\vec{B}\times \vec{l}[/tex]

where [itex]\vec{l}[/itex] has the sense of the current.
Accidents may happen and people may lose their fingers...The cross product may be forgotten...But,hey,Fleming's stupid rule may be forgotten as well.

Daniel.
 
Thanks for the help :-)
 
dextercioby said:
[tex]\vec{F_{em}}=I\vec{B}\times \vec{l}[/tex]
I think you meant:
[tex]\vec{F_{em}}=I \vec{l}\times \vec{B}[/tex]
 

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