Question regarding displacement current

AI Thread Summary
Displacement current is primarily caused by a changing electric field, as indicated by the correct answer being a). While a changing magnetic field can induce an electric field according to Faraday's law, it does not directly contribute to displacement current. The discussion highlights that the induced voltage from a capacitor's charging current is minimal and that a constant current would result in no induced voltages due to a lack of change. Clarifications emphasize that displacement current is defined solely by changes in polarization and electric field over time, excluding the magnetic field's influence. Understanding these principles is crucial for grasping the concept of displacement current in electromagnetism.
utkarshakash
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Homework Statement


Displacement current arises due to
a)changing electric field
b)changing magnetic field
c)both

Homework Equations



The Attempt at a Solution


I think the answer should be c) because we already know that changing electric field is responsible for displacement current. But if the magnetic field is also time-dependent then it will induce an electric field according to Faraday's law. So, the induced electric field will also contribute to the displacement current.
However, the correct answer is a).
 
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Others are in a far better position than I to discuss your theory, but I would make 2 comments. (1) The voltage induced in a single turn (?) of an insulating material (the dielectric) by the capacitor's charging current may be minscule. (2) Consider the special case: if you were to charge the cap from a constant-current source, the charging current would be constant and unchanging, so with di/dt =0 there would be no induced voltages anywhere.
 
NascentOxygen said:
Others are in a far better position than I to discuss your theory, but I would make 2 comments. (1) The voltage induced in a single turn (?) of an insulating material (the dielectric) by the capacitor's charging current may be minscule. (2) Consider the special case: if you were to charge the cap from a constant-current source, the charging current would be constant and unchanging, so with di/dt =0 there would be no induced voltages anywhere.

I'm sorry but it's still not clear to me.
 
Hey!

Remember that the current displacement is only defined by the change in your polarization and your change in electric field, both with respect to time.

The magnetic field has no effect on this value.
 
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