Introduction To Electricity PDF

INTRODUCTION IN ELECTRICITY  CONTENT 1-1 ELECTRICITY 1-2 DEFINITION OF TERM 1-3 ELECTRIC CURRENT 1.1. ELECTRICITY Electricity is considered as the greatest of all discoveries of man. The phenomenal importance and usefulness of electricity paved the way to the more sophisticated inve...

INTRODUCTION IN ELECTRICITY  CONTENT 1-1 ELECTRICITY 1-2 DEFINITION OF TERM 1-3 ELECTRIC CURRENT 1.1. ELECTRICITY Electricity is considered as the greatest of all discoveries of man. The phenomenal importance and usefulness of electricity paved the way to the more sophisticated inventions making what originally seemed impossible become realities. 1-2 Definition of Terms The Electron is a particle of an atom which is sometimes referred to as the negative charge of electricity. A familiar theory states that 'Anything that has mass and occupies a particular space is matter Matter is either solid, liquid or gas. An example of liquid matter is water, a molecule of water is a combination of two atoms of hydro gen and an atom of oxygen. Therefore, the molecule is a combination.  THEORY a) That all matters are made up of molecules. b) That the molecules are made up of atoms. c) That the atom contains neutrons, electrons and protons That the neutron is neutral, hence neither positively nor ne- gatively charged. d) That the electron of an atom of any substance could be transformed into another atom. The Volt or Voltage is the electrical pressure that cause the elec rons to move through a conductor (wire). In short, voltage is the 'electromotive force." Seemingly, to have 12 volts is like having 12 pounds of water pressure in a pipe. The higher the voltage the more electricity will be forced to flow. The Ampere is the flow of electricity. When there is too much flow of electricity in 9 small wire, heat is produced in the wire burn- ing the insulator. This is followed by short circuit blowing off the fuse or causing fire. The right diameter of wire for the circuit there- fore should always be specified. Circuit refers to the wire installation in the house that supplies current to light and convenient outlets. The Watt - is the rate of power used. It is the power term. It rep- resent how much is the equivalent heat volts and ampere produced if plugged to an appliance. It is a measure of the power consumed This is a common term labelled on light bulbs and appliances which gives us an idea of the kind of circuit that should be used or installed. Resistance - is the opposition or friction to the flow of current. Like for instance, the flow of water inside the pipe is subject to resistance caused by the friction of water inside the wall of the pipe including the coupling, elbow and other forms of turns and fittings  FACTORS WHICH INFLUENCE CONDUCTOR RESISTANCE A. Composition of a conductor. This refer to a conductor having free electrons which has low resistance. B.Length Resistance is high to a longer wire and low to a shorter wire. c) The cross Sectional Area. The bigger the cross sectional area of the wire the lower it's resistance. d) Temperature. Metal offers high resistance to high temperature (heat 1.3 ELECTRIC CURRENT  ELECTRIC CURRENT IS CLASSIFIED INTO: 1. Direct Current Electricity, (DC) 2. Alternating Current Electricity, (AC)  Direct Current Electricity flows in only one direction. The flowis said to be from negative to positive. The common source of direct current is the dry cell or storage battery. Alternating Current Electricity continually reverses its direction of flow. This type of electricity is generated by machinecalled ACgenerators. Alternating current is widely used due to its unlimitednumber of applications and the following advantages over the DC: 1. It is easily produced 2. It is cheaper to maintain 3. It could be distributed to farther distance with low voltage drop 4. It could be transformed into higher voltage 5. It is more efficient compared to DC