Does Applying an Electrical Field to One Side of a Conductor Double the EMF?

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SUMMARY

The discussion centers on the application of an electrical field to one side of a conductor and its effect on electromotive force (EMF). It concludes that while applying an electrical field (∑) to a conductor generates a current (I), the concept of hole current in semiconductors complicates the understanding of current flow. Specifically, the presence of holes, which represent the absence of electrons, suggests that the effective current could be perceived as doubled (2I) in semiconductors, but this does not apply to conductors where only electron movement is considered. Therefore, the resultant EMF remains ∑ for conductors, not 2∑.

PREREQUISITES
  • Understanding of Ohm's Law (V=IR)
  • Familiarity with Kirchhoff's Law
  • Knowledge of charge carriers in conductors and semiconductors
  • Basic principles of electric fields and EMF
NEXT STEPS
  • Research the differences between conductors and semiconductors regarding charge carriers
  • Explore the concept of hole current in semiconductor physics
  • Study the implications of electric fields on current flow in various materials
  • Investigate advanced models of semiconductor behavior beyond Ohm's Law
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Electrical engineers, physics students, and anyone interested in the principles of electromagnetism and semiconductor theory.

Ozgen Eren
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Assume a conductor in a rectangle shape for simplicity.

Now, if I only choose one side of this rectangle, and apply external electrical field ∑ only to it, what EMF would I create on the conductor? I would simply say ∑, however then I had the following idea, and I started to doubt if I create 2∑ instead.

Here is what bugs me:
(say ∑=I*R, kirchhoffs law: R is the conductors resistance, ∑ is the field we apply)
Since nucleus of atoms are almost stable, most current will be due to electron movement, accelerating due to the force of the electrical field. Then electrons will create a current I obviously.

However, there is this topic we covered in semiconductors class in university, that is called hole current. Since electrons move from one atom to other atom, the destination atom is should initially be positively charged to be able to get the atom. When electron completes its movement, destination atom is now neutral, but the source atom is positively charged.

Although only one electron moved physically, there is also a positively charged 'hole' moved in the opposite direction, which doubles the equivalent current, making it 2I. Then it means we had created 2∑ equivalent voltage on the semiconductor by applying only ∑ electrical field.

Do we have ∑ or 2∑ voltage as a result of this experiment?

Here is the wiki page for electron hole:
https://en.wikipedia.org/wiki/Electron_hole

In here, its stated that we treat differently to metals and semiconductors, (we ignore holes in metals) which do not answer the question but adds another dimension to it:
https://en.wikipedia.org/wiki/Charge_carrier
 
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V=IR ... here, V would be the potential difference along the conductor. This is Ohm's law, not Kirchoffs.
The electric field with the electric potential are different things.
If the same voltage gets a higher current, it means the resistance is lower.

You state at the start that the test material is a conductor... not a semiconductor.
Semiconductors don't have to obey Ohm's law.
Semicondictors are usually modeled with only one type of charge carrier ... also remember that a "hole" is the absence of an electron.

Note: where there is a minority charge carrier, you do need to account for it when figuring the current... so you'd get more current for the same voltage... which means the resistance is lower than it would be if only one carrier were present.
 
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Simon Bridge said:
Semicondictors are usually modeled with only one type of charge carrier ... also remember that a "hole" is the absence of an electron..

I think you meant conductors here...not semiconductors. Semiconductors generally have two types of charge carriers, electrons and holes. Conductors generally have only electrons contributing to conduction.
 
Dont confuse the model with reality.
 

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