Question

Why are electric transmission lines kept slightly loose when they are laid in summer?

Answer 1

Electrical wires are made up of copper which is a metal, metals conduct heat and electricity. Because of this phenomena the wire undergoes expansion and contraction every single day, thus if the wires were tightly held in the long run the wires might get snapped because of the contraction it faced.

Answer 2

Explanation:

When a solid gets heat it expands and on cooling it contracts. Due to this electrical and telephone cables are strung out a little loose so that in winter, as cables contract due to cooling of atmosphere and snapping may occur, can be avoided.