Where does the heat come from?

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SUMMARY

The discussion centers on the phenomenon of heat generation when two conductors with differing Fermi levels are placed in electric contact. Electrons flow from the conductor with a higher Fermi level to the one with a lower level until electrostatic potential equalizes the Fermi levels, creating a contact potential. This flow of current leads to either forward or reverse bias, resulting in a temperature gradient. The heat is generated as fast-moving electrons collide with the atoms of the conductor, causing them to vibrate and produce thermal energy.

PREREQUISITES
  • Understanding of Fermi levels in conductors
  • Knowledge of electrostatic potential and contact potential
  • Familiarity with electron behavior in conductive materials
  • Basic principles of thermodynamics related to heat generation
NEXT STEPS
  • Research the concept of Fermi level in detail
  • Explore the relationship between current flow and thermal energy generation
  • Learn about the principles of forward and reverse bias in semiconductor physics
  • Investigate the effects of electron collisions on atomic vibrations and heat production
USEFUL FOR

Electrical engineers, physicists, and students studying materials science or thermodynamics will benefit from this discussion, particularly those interested in the thermal effects of electrical conduction.

Mk
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When two conductors are placed in electric contact, electrons flow out of the one in which the electrons are less bound, into the one where the electrons are more bound.

The reason for this is a difference in the so-called Fermi level between the two conductors. The Fermi level represents the demarcation in energy within the conduction band of a metal, between the energy levels occupied by electrons and those that are unoccupied.

When two conductors with different Fermi levels make contact, electrons flow from the conductor with the higher level, until the change in electrostatic potential brings the two Fermi levels to the same value. (This electrostatic potential is called the contact potential.)

Current passing across the junction results in either a forward or reverse bias, resulting in a temperature gradient.
Where does the heat come from? The current going through results in heat how? The electrons moving give off heat as going to a lower energy?
 
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The fast moving electrons collide with the conductor's atoms which start to vibrate (heat).
 
Thanks, that was a good explanation.
 

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