The Force That Transformed The World (From Thierry YOUL, Lycée of Kongoussi)
In order to speak about electricity, it is necessary first to talk about the atom. The idea of the "atom" has a long history, one extending back to about 600 B.C. and the time of the ancient Greeks. They believed that all matter was made up of atoms. The word "atoms", in fact, comes from the Greek work "atoms" which means "indivisible". It was until 1897 that it was discovered that the atom is not indivisible but is composed of even smaller particles. Among these particles is one called the electron.
Electrons orbit around the center or nucleus of the atom, much as the planets in the solar system orbit around the sun. Electrons closer to the nucleus are held more highly than those in the outer orbits. It is the electron in the orbit of certain kinds of atom that can be made to flow as electric current.
Electron flow easily through certain kings of materials called "conductors". Many metals, such as silver, gold, and aluminum, are good conductors. Good conductors are used in electric circuits to provide a path for the current.
Other substances provide strong resistance to the flow of current. These substances are called insulators, which are used to confine a current to the desired path. Substances, such as hard rubber, glass wax and certain kinds of plastic, are good insulators.
The pressure that makes electrons flow along wires is called voltage. Voltage may be created by generator at a power plant or by an electric battery. When you turn on a light or an electric appliance, electrons are drawn from a generator.
It is similar to the way a water system works.
When you turn on a water faucet, water flows through the pipes, which is like electric current flowing through wires. When you turn off a faucet, water pressure remains but no water flows through the faucet. Similarly, when you turn off an electric appliance, voltage remains, but no current flows. In a water system the whole operation depends on water pressure generated by a water pimp. In an electric system, the generator (or) battery) creates the pressure called voltage.
1) Electrons and voltage stand as the key element of electricity. Justify this statement. (3 pts)
2) What transformation has electricity brought to the world? (3pts)
3) Which one of both energies (solar and hydro-electric) should Sahelian regions use? Argue your assertion (6 pts)
4) Define both renewable and non renewable energies and argue the one the world should adopt. (8 pts)