INTRODUCTION TO ELECTRICITY Objectives: At the end of the lesson, the students are expected to: 1. Define electricity. 2. Explain the electron theory in relation to electricity. 3. 2 Definition of terms o Current – is the intensity of the flow of electrons in a conductor. o Power – it is the total measure of electrical energy consumed in a circuit. 3 ELECTRON THEORY ATOM is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas and plasma is composed of neutral or ionized atoms. 4 Composition of Atoms PROTONS (+) are positively charged particles. ELECTRONS (-) are negatively charged particles. NEUTRONS (n) are neutral particles. 5 ELECTRICITY • Is a phenomenon which is known more by its effects. You can only see, feel, or hear its effect because it can produce heat, light, sound and is able to cause mechanical movements of things in a certain place or from one place to another. 6 ELECTRICITY • • Is defined as a basic form of energy that’s is a property of a certain fundamental particles of matter known as protons and electrons. Is the movement or flow of a electrons in a conductor. 7 Kinds of Electricity o Static Electricity – electricity that is not in motion or electricity at rest. It is usually generated by means of friction. Example: Lighting 8 Kinds of Electricity o Dynamic or Current Electricity – electricity in motion. It can be transmitted from one place to another. 9 Properties of Electricity o Current – is the intensity of the flow of electrons in a conductor. o Voltage – is the electromotive force (EMF) that enables or pushes the electrons to flow in a conductor toward a certain direction. o Resistance – it is the force that opposes the flow of electrons. o Power – it is the total measure of electrical energy consumed in a circuit. 10 OHM’S LAW George Simon Ohm, a German physicist discovered that voltage, current, and resistance in a circuit have definite relationship with one another. *Current (I) is directly proportional to Voltage (E) and inversely proportional to Resistance (R). 11 In simple terms, it means two things: 1. Current (I) is directly proportional to Voltage (E). - An increase in voltage will result to an increase in current. 2. Current (I) is inversely proportional to Resistance (R). - An increase in resistance will result to a decrease in current. 12 To compute: 13 GROUP ACTIVITY: In a ½ sheet of yellow paper, 14 15 16