Why is the wire loose between two electric poles, why not straight, let us know/ GK IN ENGLISH

electric poles with lose wires
You may have often noticed that the wire is seen flaccid between the two poles of electricity. Which is not very straight. The electric engineer says that all the curves in the electric wire are as much as the power loss. 
If the wire is kept straight, the cost of electricity is less. Then The question is, when the government knows this, why does it increase the cost of electricity by loosening the wire between the two electric poles? 
Is there any science behind it or negligence of employees? 
Let’s try to understand:

1. What is thermal effect, where and how much works in your life?

Dharmendra Singh Rathore, a resident of Jaipur Rajasthan, who has done Diploma Electrical Engineering & Civil Engineering (Janpat Engineering) and is working as draftsman in Pricision Design Engineering, points out that you will see a lot of examples of the electrical wires by giving a little relaxation, keeping the gap on the joint of the tracks on the railway track, keeping the gap on the cement concrete road joints, placing space in the joints of the road bridge, etc. There are a lot of factors, but one of the most prominent and common factors is thermal effects.

Understand this carefully

We have all seen and realised that whenever a metal is hot, it is spread and when it is cold, shrinkage or contraction sehasare. It is a natural phenomenon that is equally applicable to almost all metals, although in some metals this effect is less, but it must happen.

2. Why the wire between the pillars is left loose?

When the temperature is very low in winter, the electric wires (which are normally made of aluminium and steel) cause shrinkage due to their thermal nature and try to reduce their area. In this situation, if the wire is completely tightly tied, it will force the pillars that are tied up and consequently increase the stress, which is possible to break the wires, or tilt the pillar inward. 
Since the transmission line is hundreds of kilometres long, the total impact will be very high, which can damage any transmission line from a large space. So to eliminate this effect, the wires are hung and tied, which is called SAG in technical language.
There are many other facts behind it, Which are as follows
  • Load due to air
  • Load due to snow
  • Own weight of conductor (wire)
  • Distance between two poles

Even because of gravity, the wires cannot be kept straight.

And most importantly, you cannot keep any wire upright in any case, it is impossible, even if the saig is not given, it will come automatically, because all the wires must have their own weight which must tilt the wire downwards because of the gravitational effect. However, it will be less in that case.