# How does loss of energy happen in current flow?

I don't understand how current electricity loses energy while it travels from station to our home appliances and back to station. Does it keep on losing energy and become useless? Can't we use the same current flow to all houses? How does current electricity "finish" as it travels through many houses from station?

• What do you mean by "finish"? – Steeven Nov 14 '15 at 16:02

There are lot of phenomenons in electric current, that lead to loss of energy.

1) An alternating current (AC) works the way that electrons in the wire get accelerated forth and back 50 times per second (50 Hz in Europe, 60 Hz in other regions). Any electron acceleration is accompanied by the induction of a magnetic field. This magnetic field led to some deflection of the moving electrons away from the straight movement through the wire. This is accompanied with something like vibrations of the molecular structure of the wire and this lead to heat dissipation and heat radiation.

2) Even if one use direct current (DC), the electrons, set in motion by magnetic fields of a generator in power plant, are the reason for heat dissipation and electromagnetic radiation. Electrons could flow through a wire without energy loss only in superconductive materials and only with temperatures of approx. minus 180°C. In all other cases the electrons bounce on the wire molecular structure, get braked (a kind of acceleration!) and accelerated (in the common sense) and this led to electromagnetic radiation.

3) Wires are not going straight in a line from the generator to the consumers. Any curvature of the wire led to an acceleration of the electrons in the current (any deflection of a body is an acceleration). This led to the induction of a magnetic field and so on (see point 1 and 2). 4) Any use of electric current is accompanied with magnetic fields and heat dissipation.

5) The phenomenon of production of an electric current one can see easily by a (perhaps old) bicycle. There was a small dynamo and a bulb, connected by two wires.

The dynamo (or generator) has rotating magnets and a coil around. The electrons, due to their magnetic properties (yes, they have not only a electric charge), get accelerated and pushed into the wire at the end of the coil. At the same time at the beginning of the coil the electrons from the back running wire get sucked into the coil. If between the running out and comming in wire is nothing, one produces only heat. If one put in a LED, one get light and heat. Puting between a fan, one get air stream and heat. You name it ...

A wonderful property of such a connection is that all the users get electric energy of the same voltage and all the devices are designed for this voltage. To get the details, you only has to know, that each distributor - depending of his power consumption get his amount of electrons (this flow of electrons one call electric current), but the voltage is nearly the same.

Current loses energy through collisions of its carriers which are electrons. Electrons in a wire move in a definite direction and this motion in a definite direction is what we call current. But there is one missconception in your question. Current does not travel from a station to our home. In stead, all the electrons that are just siting there in your wires at home start moving at once, in the moment you switch on a light or a dishwasher or whatever. So, what actually travels through the wires to your home is some kind of signal, electric field which moves all of the electrons at the same time. Current loses energy through the process of collision. As we all know, in the wire there are free electrons and there are atoms, ions, which constitute a cristal lattice. Collisions of electrons with a cristal lattice and with other electrons are the processes which turn useful energy of an electric current into heat, which is not that useful.So organized motion of electrons becomes unorganized. Long wires lose more of the energy, of course, because there are more collisions of electrons while they travel. Cross section of a wire plays a role too. Bigger cross section means less resistance while smaller crosssection means more resistnce. These are the properties o the wire but there is also a property of a material which we call resistivity. It describes how much resistance would a given wire have depending on a material. This is a short answer but the problem of electrical resistivity and electrons in a metal is much more complicated. For example, it is not the collisions with a lattice as such which cause energy loses, it is the vibration of a lattice and scattering of electrons off these vibrations.

The term current is actually improper term. The electricity has two components to put it in simple terms. Current and Voltage. The supply that we get in our homes in AC supply as to the old system of Dc supply.

The AC supply of the poly phase alternating current system invented by Nicola Tesla is the modern ac supply.

The current never gets less as it goes form house to house because the grid supply is stepped down at every locality by transformer, and each house is given the exactly equal power.

The main grid supply can not be given because it has very high voltage. and large systems need to be installed at homes which is quite dangerous.

The homes are connected in series connection and not in parallel connection so there in drop in voltage only the current is divided. And honestly we use only about 5 to 10 Ampere current

The power supply is measured in Voltage and not in ampere. Each and every house gets 110 V if you are in America or 220 V if you are in country like India.

If your question is how is the effect of power loss in a load or resistance, then the answer is elaborately described above.