1. Technological World

2. What is electrical engineering? Designing and developing objects which use electricity, electronics and electrical circuits is the work of electrical engineers. Electrical engineering covers two main areas: Electricity Electronics

3. Electricity & Electronics All electrical appliances and electronic devices depend on electrical circuits. The main difference between electricity & electronics lies in the design of these electrical circuit components.

4. Electricity Materials used for electrical components are: metals & alloys (especially copper) – these are known as conductors. Electrical components have potentially powerful currents. Electrical components have circuits of normal size.

5. Electronics Materials used for electronic components are: materials such as silicon – these are known as semiconductors. Electronic components have low-intensity currents. Electronic components have miniaturized circuits.

6. Circuit Diagrams Circuit diagrams are symbolic representations showing how different electrical components fit together to form a whole.

7. Circuit Diagrams Conventional symbols are used to represent the components which make up a circuit diagram.

8. Electrical/Electronic Circuits All circuits carry an electric current. The conventional current direction flows from the POSITIVE terminal of the power supply to the NEGATIVE terminal.

9. Electrical/Electronic Circuits On the other hand, the electron flow occurs in the opposite direction from the NEGATIVE terminal to the POSITIVE terminal.

11. Direct & Alternating Current Electric current can be described as direct or alternating depending on the way electrons flow through the circuit.

12. Direct Current Direct current (DC) is an electrical current in which the electrons move continuously in the SAME direction. Electrons move in only ONE direction. A battery is one example of a source of direct current.

13. Alternating Current Alternating current is an electric current in which the electrons move BACK AND FORTH in a regular pattern. Electrons move in BOTH directions. Power plants are examples of sources of alternating current.