NOW A days, we are facing the issue of energy. Energy in terms of electricity and light. Both electricity and light are mysterious. We are well aware of their effect, but, if asked the question “what is electricity?” or “what is light?”, we have a difficulty giving a convincing answer. We find it easiest to think in terms of a model, or models, which make it possible for us to understand how an electrical or optical device works. Provided the model, or “mind picture”, is consistent, this is a quite acceptable way to proceed – indeed it is the only way for the layman to get an insight into physical processes. In this article I describe the simplest models of electricity and light to the point where the methods of controlling them can be understood. The first model we need is that of the structure of matter. The atomic theory holds that the smallest unit of matter is the atom. In a compound there are several different kinds of atom, but in an element all the atoms are the same. All atoms are themselves made up of fundamental particles. Modern physics has produced an alarmingly long list of these, but for our purposes it is sufficient to know of only three:
• the proton, a massive particle which carries a positive electric charge
• the neutron which has the same mass as the proton, but has no charge
• the electron which carries a negative electric charge equal and opposite to that of the proton.
This model is similar to the solar system or the planetory system.
When the first electrical discoveries were made, it was a convention that electric current flowed from the positive terminal of a battery to the negative terminal. This convention remains today, even though our “electron flow” model of electricity found that the conductor heats up while the current flows, and that this heating effect is proportional to the square of the current. What is current? Actually it is the flow of free electrons in a conductor that flows from high potential to low potential. These free electrons belong to atoms that is described earlier in the article this flow occur due to difference of energy applied to the conductor it is the simplest model to understand what is Electricity. In the real world the e.m.f (electro motive force/energy) of the battery measured on open circuit (nothing connected) only equals the p.d. across the load resistance when connected if the battery itself has no internal resistance.
The electricity which arrives in our home is Alternating Current or AC. The reason for this is that it is both easier to generate, and easier to distribute. AC minimizes the loss of electrical energy to the consumer. Different equipments are used to maintain the correct value of the AC Voltages.
Now how the light is produced according to our model atom consist of basic particle known as electron when externally the energy is applied to the atom it excites the electron and that electron jumps into high energy level, and that electron when comes in the lower energy level it emits the energy which is the difference of the higher to lower energy level energy. It is the simplest model to understand the concept of light and Electricity.
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