Isu Physics Essay Research Paper ELECTRICITY ISU

Isu Physics Essay, Research Paper

ELECTRICITY I.S.U. There are two electric states. Benjamin Franklin identified them as positive and negative charges. All objects possess electricity and a neutral object possess a normal amount. For purposes of identification ; Negative = The charge that an ebonite rod acquires when rubbed with fur. Accordingly , any other charged object that is repelled by such a charged object that is attracted to a charged ebonite rod , such as a glass rod rubbed with silk , must be charged positively. Therefore the Law of Electric Charges can be stated as follows. 1) Opposite charges attract each other. 2) Similar charges repel each other. 3) Charged objects attract some neutral objects. All matter is composed of atoms which contain different charges, positive, negative and neutral charges. Each charge is carried in a particle known as either a proton, electron and neutron. Protons are found in the nucleus of the atom. They are small, heavy and have a positive charge of a certain magnitude known as an “elementary charge”, electrons are found moving around in the orbits of the nucleus which contain a negtive charge. Each one is 1/2000th the mass of a proton and has a charge of same magnitude. Neutrons are also found in the nucleus which contain a neutral charge and a re small heavy particles. All matter falls into one of the three categories, which are conductors, semi-conductors and insulators. A conductor is a solid in which electrons are able to move easily from one atom to another. Some of the best conductors are metals such as aluminum, copper, and silver. Some of the electrons in conductors can be classified as “free electrons”. This is because they have the ability to move about within the atomic framework of a solid. A semi-conductor is an intermediate between a conductor and an insulator. This is because it contains very few “free electrons”. These substances become excellent conductors after a small impurity is added in a proccess called “doping”. All semi-conductors are solid at normal temperatures. An insulator is a solid in which the electrons are not free to move about from atom to atom. Some examples of good insulators are cork, glass, plastic, and wood. Solids become conductors when they have a great amount of “free electrons” given the electron the ability to transfer from atom to atom. Certain liquids are also conductors of electricity. This is because the molecules of a liquid are free to move about. The liquid will become a conductor if the particles are charged (positive and negative ions). This occurs, for example, when some chemicals are added to water to dissociate (break apart) into positive and negative ions when dissolved. Gasses also can be classified as conductors and insulators, depending on the electrical nature of the molecules. For example, air is an insulator until exposed to X-rays or radiation which causes the molecules to ionize and become conductors. Plasma is a collection of very hot positive and negative ions and electrons, which make it a good conductor. Some examples of plasma are neon lights to nuclear fusion reactors. 2. Some methods of charge transfer:a) Charge by friction Some substances acquire an electric charge when rubbed with another substance. An example of this is the ebonite rod that became negatively charged when rubbed with fur. The atoms of the ebonite rod capture some of the electrons from the fur, this then exerts stronger forces of attraction on them than do the atoms making up the fur. Therefore, after rubbing the ebonite rod has an excess of electrons and the fur has a deficit. The same explanation can be said for other pairs rubbed together. These can be determined by the Electrostatic Series, which is a list of substances in a specific order which determine which substances are greater in positive and negative charge when rubbed together. b) Induced Charge Separation When an ebonite rd negatively charged is brought near a metallic- coated pith-ball or metal leaf electroscope ( A simple device which is used to detect and compare electric charges. A transferred charge spreads out over the entire conducting system causing the leaves to diverge and indicate an electrical charge.) with metal a neutral charge, some of the free electrons are repelled by the ebonite rod and move to the far side of the ball or leaf. The negative distribution of charge on the rod causes the separation of the charge on each object, this is known as induced charge separation. This can also result from the presence of a positively charged rod. c) Charging by contact This transfer of charge occurs when two or more substances come into contact. For example , when a negatively charged ebonite rod is touched to a neutral pith-ball, they tend to share electrons to give both objects a negative charge. Likewise when a positive charged rod is used, both objects will share electrons to be given a positive charge. ” An object charged by contact has the same sign as the charging rod. d) Charging by Induction When a charged ebonite rod as brought near an electroscope, free electrons on the electroscope tend to move away from the negative charge. When the electroscope is touched by your finger, it creates an alternatepath for the negative charge to follow. This process is known as electrical grounding . This also leaves the electroscope with a deficit of electrons and a positive charge. When a positive rod is held near the electroscope, it ind