Question related to electromagnetic theory

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SUMMARY

The discussion centers on the phenomenon of sparking across switch contacts in a circuit containing an iron-cored inductor, a switch, and a DC source. When the switch is closed, a steady current flows through the inductor, generating a magnetic field. Upon reopening the switch, the interruption of current leads to a rapid change in the magnetic field, inducing a back electromotive force (back EMF) that can generate a high voltage. This high voltage is sufficient to create a spark across the switch contacts as the circuit attempts to maintain current flow.

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  • Understanding of electromagnetic induction principles
  • Familiarity with back electromotive force (back EMF)
  • Knowledge of circuit components, specifically inductors
  • Basic grasp of DC circuit behavior
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Question:
A circuit contains an iron cored inductor, a switch and a DC source arranged in series. The switch is closed and after an interval reopened. Explain why a spark jumps across the switch contacts.
Attempt:
I guess it's related to self induction and back emf but am unable to understand how a spark can be produced in such a case...
 
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on the right track, to produce an electrical arc, you first need quite a large voltage...

thinking about what's going on, before opening the switch you have a steady flow of current through the inductor, which produces a magnetic field

when you open the switch you immediately intererupt the current & so the magnetic field...

can you find any equations to help explain what is going on...
 

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