A forum set up for physics questions from students in the courses PHYS1121, 1131, 1221 and 1331 at the University of New South Wales. It is intended for questions that cannot readily be answered in class,
either because they fall outside the main syllabus and therefore would be distraction (however interesting) or for other reasons.

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Boris Lagutin


Post by Boris Lagutin »

Could someone clarify how the process called "Resistance" happens in a resistor, for example, a filament in a bulb in detail? In other words, why does the speed of the current electrons slow down in the resistor (filament)? I would like to ask to explain this process in detail as far as possible to see general elements of the process. I mean I want to know why electrons slow down and emission of light and heat happens?

Thanks a lot.
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Re: Resistance?

Post by joe »

On average, the electrons don't slow down. Rather, resistance has the effect that a non-zero electric field is necessary to maintain an average speed. See the section on this in Physclips:

The work done by that field on the electrons is turned into heat by interactions between the electrons and the lattice.

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