Why Doesn't Current Flow Continuously When Magnetic Flux is Permanently Changed?

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Discussion Overview

The discussion revolves around the behavior of electric current in response to changes in magnetic flux, specifically addressing why current does not flow continuously when magnetic flux is permanently altered. The scope includes theoretical concepts from electromagnetism, particularly Lenz's law and Faraday's law.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions why current does not flow continuously to maintain a constant magnetic flux when it is permanently changed.
  • Another participant clarifies that current does not aim to keep the flux constant; instead, charges respond to changes in flux.
  • A further response emphasizes that the current produced in a coil is proportional to the rate of change of the magnetic flux, indicating that once the change ceases, so does the current.
  • It is noted that Faraday's and Lenz's laws pertain to induced electromotive forces (emfs) rather than currents, highlighting a distinction between the two concepts.
  • A participant introduces the idea that relative motion between the conductor and magnetic field is necessary to generate emf, seeking clarification on this point.
  • Another participant suggests that the relationship between electric and magnetic fields is a fundamental aspect of how the universe operates, implying a deeper connection to physical laws.

Areas of Agreement / Disagreement

Participants express differing views on the nature of current flow in relation to magnetic flux changes, with some clarifying concepts while others seek further understanding. No consensus is reached on the implications of these laws.

Contextual Notes

The discussion includes assumptions about the nature of induced emf and the conditions under which current flows, which may not be fully articulated or agreed upon by all participants.

Karan Punjabi
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Guys, I have read Lenz's law and Faraday's law. My question is when the current is overall trying to keep the magnetic flux constant as that in initial time then if I permanently change the flux then why the current is not flowing through the conductor continuously to keep initial flux constant. Thankyou
 
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The current is not trying to keep the flux constant - the charges respond to changes in flux.
 
Simon Bridge said:
The current is not trying to keep the flux constant - the charges respond to changes in flux.
Can you elaborate please. Because I want real concept. I want to understand it.
 
Simon Bridge said:
the charges respond to changes in flux.

In other words current produced by changing the flux in a coil is proportional to the time rate of change of the flux in that coil. Once the change stops the current stops, end of story. In order to sustain the current you must continuously change the flux.
 
Faradays and Lenz's laws concern induced emfs...not currents.
There is a very subtle but important distinction.
You will always get an induced emf in a conductor when there is a changing magnetic flux linkage. This does not mean that you will always get a current.
 
Ohk...I read an article and there I concluded that there must be a relative motion between conductor and magnetic field to generate EMF. Why it is like that?
 
Its a consequence of electrical and magnetic fields being manifestations of the same fundamental force and the invariance of the speed of light. Bottom line: it happens because that is how the Universe works.

What was the article? Where?
 

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