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Secondaire 4 • 1m


I recently asked a question on electromagnetic induction and I'm unsure about the explanation I have received. The question I asked was: If a magnet is placed near a coil with an iron core inside of it, given the scenario and the information provided, in order to generate an electric current would the action to take be moving the magnet arond the coil or moving the iron core of the coil in and out? The answer I was provided was that the action to take was moving the core in and out of the coil. However, from my standpoint, when you move the magnet placed near the coil, you change the magnetic field that passes through the coil. According to Faraday's law of electromagnetic induction, an changing magnetic flux induces an electromotive force in the coil causing the flow of an electric current. Therefore, given the information that there is an additional magnet placed near the coil, I don't understand why the action to take would be to move the core inside and out of the coil.

Thank you.


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Explications (1)

  • Explication d'Alloprof

    Explication d'Alloprof

    Cette explication a été donnée par un membre de l'équipe d'Alloprof.

    Équipe Alloprof • 27j

    Hi there!

    Thank you for your patience! Your question was a complex one!

    In fact, you would need one part or the other to move in order to create an electric current. As you said, you would need to move the magnet around to generate current. If the core and the magnet moved at the same time (not at the same speed or the same direction), it would create a current. Moving only the core wouldn't exactly change the electromagnetic field. However, if the core was magnetic, it could change the electromagnetic field. It wasn't mentioned in your question, so I guessed it wasn't magnetic. Moving only the core could mean a small change in the electromagnetic field, but not enough to say that it has created a current.

    To learn more about electromagnetic current, follow the link:

    Hope that cleared it up!

    Have a great day :)


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