We often see wire having kinks or bends. Will these bends affect the resistance of the wire?


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Tim Cook Profile
Tim Cook answered

It depends on the bend! A wire bent back or kinked just once or twice is very unlikely to have its resistance affected. However, if a wire has been bent back and forth multiple times, then there can be a slight increase in its resistance.

You have to remember that what looks like a large kink in a wire to the human eye is negligible to a proton. The size of a proton is around 0.85 of femtometer, and you can fit 100,000,0000 femtometers into a distance of 0.001 of a millimeter, so a bend in something as relatively thick as a copper wire will make no difference to a flow of protons.

Back and Forth, Back and Forth

If a wire is bent often enough at same point over time, then this may affect the structure of the copper wiring at an atomic level. Imagine it as your hand passing over material or wood in a way that 'goes against the grain'; your hand can pass along it well enough, but the resistance is increased. This is what happens to copper wiring if bent often enough, the 'grain' is damaged.

Even in this case however, the disruption to the proton flow is likely to be minor. 

To read similar Blurtit questions on this topic, go to Is The Smooth Or Ribbed Wire Hot? or Does The Thickness Of The Wire Affect The Power Of The Electromagnet?

Understanding the nature of electrical resistance is a fundamental part of physics. Luckily, there are YouTube users ready to make it easier to understand, as you can see:

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