Will capacitors react to external electric field

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Discussion Overview

The discussion centers on whether a capacitor exposed to an external electric field, whether changing or static, will have a voltage induced across its plates. The scope includes theoretical considerations and practical examples related to electric and magnetic fields.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant describes the creation of an electric field in a capacitor when charged by a voltage source and questions the effect of an external electric field on the capacitor.
  • Another participant argues that the concept of an "external" electric field is problematic, suggesting that the electric field cannot exist as depicted because the wires of ideal conductors are at the same potential.
  • A different participant proposes various methods to create external electric fields, including using a Van de Graaff generator, changing current in a solenoid coil, and referencing a specific transformer that charges a capacitor via a changing magnetic field.
  • One participant responds by asserting that the fields created in the proposed methods are internal to the capacitor circuit, agreeing that this would lead to a voltage in the capacitor circuit.

Areas of Agreement / Disagreement

Participants express differing views on the existence and definition of external electric fields and their effects on capacitors. The discussion remains unresolved regarding the implications of these fields on voltage induction across capacitor plates.

Contextual Notes

The discussion highlights limitations in defining "external" electric fields and the assumptions regarding ideal conductors and their potentials. The implications of changing magnetic fields on electric fields and capacitors are also not fully resolved.

Narayanan KR
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magnetic.png

1. Passage of current via coil creates magnetic field (fig a), similarly external magnetic field linked to coil when changed created electric current in the circuit connected ( Faraday's em induction fig b).
2. Charging of capacitor using voltage source creates electric field in the capacitor (fig c)
But the question is if a capacitor exposed to an external electric field (changing or static, fig d) will there be a voltage induced across the plates of the capacitor ? all your answers are welcomed.
 
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The electric field as in your sketch cannot exist - it goes along the wires, but the wires of (ideal) conductors are at the same potential.
The definition of an "external" field is quite tricky, partially due to this problem.
 
Bro there are many ways to create external electric fields in real.
1. Sphere of van de graff generator
2. You take a simple solinoid coil and change the current through it, then the magnetic field will change because of which there will be electric field created in space perpendicular to changing magnetic field.
3. lastly check out this on google "mislavskij transformer" where a guy charges a capacitor with electric field that resulted because of a changing magnetic field of a coil
Mislavskij-Transformer-P1 (1).jpg
 
Then you are creating a field inside. Not that external. Yes, that will lead to a voltage in the capacitor circuit.
 
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