Direction of induced current in the loop

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SUMMARY

The discussion centers on the treatment of a moving electron as an infinitesimal current element in the context of induced current in a loop. The participant correctly applies the Biot-Savart law to explain how the magnetic field changes as the electron moves, leading to a reversal in the direction of electromotive force (EMF) and induced current. The conclusion confirms that the reasoning is valid for introductory physics, particularly in relation to option 4 of a multiple-choice question regarding induced current direction.

PREREQUISITES
  • Understanding of Biot-Savart law
  • Familiarity with electromotive force (EMF)
  • Basic knowledge of electric current and charge movement
  • Concept of induced current in electromagnetic theory
NEXT STEPS
  • Study the Liénard-Wiechert potentials for moving charges
  • Explore advanced applications of the Biot-Savart law in electromagnetic fields
  • Learn about Faraday's law of electromagnetic induction
  • Investigate the relationship between current, magnetic fields, and induced EMF
USEFUL FOR

Students of physics, educators teaching electromagnetism, and anyone interested in understanding the principles of induced current and electromagnetic fields.

Jahnavi
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Homework Statement


electron-induced current.png


Homework Equations

The Attempt at a Solution



I am having a little doubt as to how to think of the moving electron as a current .

I am considering the moving electron as a very tiny (infinitesimal ) current element . It is as if when the electron is at A , there is a very tiny current element at A . As electron moves from A to B , this small current element also shifts it's position continuously from A to B .

From Biot - Savart law , we see that the magnetic field depends on the distance . As the distance first decreases and then increases, the magnitude of magnetic field through the loop first increases , then decreases .The direction of EMF and induced current reverses direction .Option 4) is correct .

Is my reasoning correct ? More importantly is it correct to treat moving electron as a tiny current element which continuously changes its position ?
 

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Jahnavi said:
Is my reasoning correct ? More importantly is it correct to treat moving electron as a tiny current element which continuously changes its position ?
See here for the correct treatment of a moving charge and the fields it generates.
https://en.wikipedia.org/wiki/Liénard–Wiechert_potential
For the purposes of answering the multiple choice question in an introductory physics context, your reasoning is good enough.
 
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Thanks !
 

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