Why Is There No Internal Electric Field in a Neutral Conductor?

In summary, the conversation discusses the placement of a conductor with a neutral total charge in an electric field. It is explained that the charges in the conductor will be arranged on the surface, with negative charges against the external field and positive charges in the direction of the field. The speaker questions whether there is an internal electric field within the conductor and asks for an explanation without using advanced mathematics. Another member responds that there is a brief period of time where an internal field exists, but it is quickly canceled out by the surface charges. The conversation concludes by discussing the duration of the internal field.
  • #1
Sheepwall
15
0
Hello, members of physics forums. This is my first post and question. As such, it will be quite basic. In an electric field, a conductor with a neutral total charge is placed. All the charges in the conductor will be on the surface, negative charges against the external electric field, positive charges in the direction the external electric field is pointing.

According to me, there should be an internal electric field; if a negative test charge is placed within the conductor, wouldn't said charge move towards the positive charges on the surface of the conductor? Wouldn't that suggest an internal electric field?

I know that I am wrong. I want to know why I am wrong. Is there a way of not bringing mathematics (unless very basic proportionality) into the explanation; I find it not very pedagogical. (Don't judge, I love mathematics.)

Thanks in advance, fellow earthlings.
 
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  • #2
For any conductor which is immersed in a static electric field, the induced surface charges will be arranged so that the field internal to the conductor is canceled ... this only takes a few femtoseconds ... if the internal field were not yet cancelled, more of the internal free charges would be shifted so as to accomplish this.
 
  • #3
The field lasts for about a nanosecond, by which time the charge has reached the surface, and the interior field is zero.
 

1. What is a conductor within a capacitor?

A conductor within a capacitor is an object that is placed between the two plates of a capacitor. This object serves as a medium for the electric charge to pass through, allowing the capacitor to store and release energy.

2. How does a conductor affect the capacitance of a capacitor?

A conductor within a capacitor affects the capacitance by increasing the ability of the capacitor to store charge. This is because the conductor acts as an additional plate, increasing the surface area of the capacitor and therefore increasing its capacitance.

3. Can any material be used as a conductor within a capacitor?

Yes, any material that allows the flow of electric charge can be used as a conductor within a capacitor. This includes metals, such as copper or aluminum, as well as non-metallic conductors like water or human body.

4. How does the position of the conductor affect the electric field within a capacitor?

The position of the conductor within a capacitor does not affect the electric field between the plates. However, it does affect the electric potential difference between the plates, as the presence of the conductor will decrease the potential difference.

5. What is the purpose of a conductor within a capacitor?

The purpose of a conductor within a capacitor is to increase the capacitance and therefore the energy storage capacity of the capacitor. It also allows for a more efficient transfer of charge, making the capacitor more effective in its use.

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