Originally Answered: Why are the electric lines never hung tautly between the two poles? Linear expansivity of metals: Under sustained relatively high temperatures, metals tend to expand. As a result, engineers have to plan for this in foresight and therefore, metal wires are never hung tightly.
Why are electric wires not hung tightly?
The reason is to minimize the tension in the wire. The wires expand when exposed to intense heat from sun and contract during cold weather. Stretching the wire and connecting to the poles will make the wires loosen up and tear easily. This might lead to an accident.
Why electric cables are always kept sagging instead of stretching?
The lines are often heavily loaded because of increased power consumption, and the conductors, which are generally made of copper or aluminum, expand when heated. That expansion increases the slack between transmission line structures, causing them to sag.
Why are cables left loose?
Cables are good conductor of heat . … So, the cable are often left loose so that they can’t break in cold days due to tension in cables.
Why are wires loose?
This can happen even if the wire is still connected to an outlet, but the outlet’s terminal screw isn’t tightened enough. In other situations, completely loose wires can come in contact with electrical boxes or other wires, possibly resulting in a tripped breaker—or worse.
Why are electric transmission wires stretched tightly when they are laid in winter?
the electric transmission lines are stretched tightly in winter due to the decrease in temperature where the wires contract and in summer the situation is opposite . The thermal expansion due to heat loosens and expands the wires..
Why is there a gap between telephone wires?
Telephone wires are kept slightly loose when they are laid because heat. … Therefore, without a slack they could become too tight and break in winters or pull loose from their anchors in summers . This is the reason why wires are kept slightly loose when they are laid.
What is sagging in electrical?
In a transmission line, sag is defined as the vertical difference in level between points of support (most commonly transmission towers) and the lowest point of the conductor. … In the above overhead conductor AOB, S is the sag when measured vertically.
Why is an electric cable usually covered with plastic covering?
Complete step by step answer Electrical wires are covered with a layer of plastic to make it safe. Plastics are non-reactive and poor conductors of electricity or to be precise, they are insulators. They do not allow the electric current to pass through them easily.
Why do electric wires sag in the summer?
Because the cores of overhead wires are made from copper. Metals expand with heat and contract with cold. The higher temperatures in summer make the copper expand – so the lines get slightly longer. In winter, the reverse happens – the lines contract and tighten up.
What is the advantage of leaving some slack when installing electrical cables like these?
The main purpose of providing slack in electrical cables is to prevent the effects of thermal stress in them. Most materials expand when heated and contract when cooled. This can be easily observed by heating a metal object (preferably made of iron) and cooling it after it has melted.
What is the material of fuse wire?
Solution: Fuse wire is made of alloy of lead and tin having low melting point of 200°C.
What happens if you connect the wrong electrical wires?
But here’s the catch: If you connect the circuit wires to the wrong terminals on an outlet, the outlet will still work but the polarity will be backward. When this happens, a lamp, for example, will have its bulb socket sleeve energized rather than the little tab inside the socket.
Can loose wires cause a fire?
Loose connections or faulty wiring in your home causes arcing and sparking, resulting in a small fire that chars or discolors your outlet.
Why are loose wires dangerous?
Loose Wiring and Connections Are Risky
The smaller strands of wiring will not be enough to efficiently transfer electricity and will heat up from the additional current running through it. Oftentimes these cause arcs of electricity. This causes your outlet to get hot and increases the chance of a fire.