Does Wire Length Affect Resistance?

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SUMMARY

The discussion centers on the relationship between wire length and resistance, specifically addressing a claim that doubling the length of a wire keeps its volume constant. Participants clarify that if a wire is stretched, its cross-sectional area decreases, maintaining constant volume under the assumption of unchanged density. However, if the wire is simply joined end-to-end, its resistance will double due to the increased length. The ambiguity in the original question led to confusion regarding the interpretation of "doubling" the wire length.

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  • Understanding of electrical resistance and Ohm's Law
  • Basic knowledge of material properties, specifically density
  • Familiarity with the concept of volume in relation to geometry
  • Knowledge of wire characteristics, including cross-sectional area
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  • Research the relationship between wire length and resistance using Ohm's Law
  • Explore the effects of cross-sectional area on electrical resistance
  • Study the principles of material density and its impact on volume
  • Investigate practical applications of resistance in electrical circuits
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Students in physics or electrical engineering, educators teaching concepts of resistance, and professionals involved in electrical design and circuit analysis.

terryds
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Do not accept any sentence you read on the Net.

That first post you refer to assumes that the volume of the wire is kept constant. So you stretch out a piece of wire and see how its resistance changes.
 
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Volume of wire is the area of the cross section of the wire times its length - excluding any wire that has varying thickness, for now. Volume remains the same if the wire is somehow going to get "thinner" when it's being stretched.
 
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well if we assume that the density of the wire doesn't change then volume= mass/density... as mass of the wire is constant the volume has to be constant
 
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The op at that link wasn't clear what he meant by the length of wire being doubled so the person that answered assumed he meant stretched. In which case the volume would be constant.

I believe the op actually meant doubled as in two lengths joined together. In which case the resistance would double.
 
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CWatters said:
The op at that link wasn't clear what he meant by the length of wire being doubled so the person that answered assumed he meant stretched. In which case the volume would be constant.

I believe the op actually meant doubled as in two lengths joined together. In which case the resistance would double.

totally agree with that summary ... unclear question leading to a incorrect answer
 

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