CIRCUIT BASIC GRADE 8 SCIENCE CHUCHU .pptx

grade 8

1. Basic electric circuit Prepared by: Ms. Gella L. Benson

2. Components of an Electric Circuit All electric circuits have at least three components: a voltage source , conducting wires , and loads . They may have other parts as well, such as switches .

3. 1.) Voltage Source is a device that maintains a constant amount of voltage. Common voltage sources used at home are battery, generator, wall socket, and electric outlet.

4. 2 .) Conducting Wires are special kind of conductors where current can pass through easily. There is a corresponding safe amount of current that can pass through for every size, thickness, or cross-sectional area of conducting wire. So, it is important to consider the dimension of wire to be used when connecting a load or number of loads in a circuit.

5. 3.) Electrical Switch is a device that can control the entrance of current. When it is on, the circuit is closed, then current can pass through. When it is off, the circuit is open, and current cannot pass through.

6. 4 .) Electrical Load is an electrical device that converts electrical energy to heat like in the case of electric iron, and to light and heat like in the case of a light bulb.

7. Voltage Source Electrical Switch Conducting Wires Electrical Load

8. Series VS parallel circuit

9. SERIES Circuit

10. PARALLEL Circuit

11. Safety devices in homes

12. Circuit BREAKERS A circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by overcurrent/overload or short circuit. Its basic function is to interrupt current flow after protective relays detect a fault.

13. Circuit Breakers

14. FUSES The fuse breaks the circuit if a fault in an appliance causes too much current to flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.

15. Fuses

16. EARTHING It is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault.

17. Earthing

18. DOUBLE INSULATION Double Insulation is the additional insulation barrier added to an electrical device to protect the user from electrical shock in the event the fundamental functional electrical insulation system should ever fail.

19. Double Insulation in Wires

20. Long exam tomorrow!