January 06, 2014

Do bends in a wire effect its resistance?


Ans.It shouldn't, unless the bend is specifically a coil, where the physics is different. There are 4 factors that can affect R:

1. Length of the conductor
2. Area of cross section of the conductor
3. Electrical Resistivity of Substances
4. Effect of Temperature

But if any bend produces stress in the wire (compression on the inside, tension on the outside) and this stress affects resistivity and hence resistance.

Secondly, because metals are more easily stretched than compressed, in general the wire will get SLIGHTLY longer and thinner when its bent (or straightened)
and if its kinked the effect will be even greater.