What Do I Do If I Get This Job?
Jobs & Education2 mins ago
No best answer has yet been selected by richb14. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.Generally power lines are made from aluminium 'rope'. It's not such a good conductor as copper but it's so much cheaper that it can be made thicker to be as good a conductor as copper and it's stronger in its own right.
All power lines do heat up when carrying their load, there is huge difference throughout the day between when they're carrying peak load (mealtimes, commercial breaks etc) and when they are only carrying normal consumption current. This results in changes in length (sagging) because the more current (power) the lines are conducting the hotter they get (just like an electric fire gets hot when you turn it on). As previously explained the hotter they get, the more they expand.
Additonally, again as said before, the variation in ambient temperature causes them to heat up even more and then cool down during the day causing them to expand and contract.
apparently it's mostly the ambient temperature that matters, not heat generated by electricity,
otherwise the wires would be looser in winter ! because in winter we consume more power.
I don't think the wires generate much heat, because they carry a very high voltage and low current. That is how they avoid to waste energy.