T3t1 Electrical circuits Gr. 6 2015

Key words Electric circuit A system that transfers electrical energy from the source to where it is needed. Electrical current The electrical charge that flows through a circuit.

Cell Battery

Key words Battery A number of cells connected together. Switch Controls the flow of electricity in a circuit. It can switch the current on or off. Input devices A cell or battery that makes the charges flow. Process devices Component that controls the flow of charges, for example the switch. Output devices Components that changes the electrical energy into useful energy, for example a light bulb.

Light bulb = Output device Switch = Process device Copy Light bulb = Output device Switch = Process device Battery = Input device

Open circuit An electrical circuit that does not allow charges to flow. Closed circuit An electrical circuit that allows charge to flow. Open circuit Closed circuit

Electric charge (Copy) All matter (solids, liquids and gasses) are made up of particles, called atoms. Some of these particles have a positive or negative charge. Charges attract or repel each other. Like charges (the same) repel each other, while unlike (not the same) charges attract. Wires in a circuit are made of metal, these wires have charges that can move, because metal is a good conductor of electricity. We can make these charges move in the same direction, we call this the flow of electricity through the wires.

Circuits (Copy) All electrical circuits have 3 basic requirements: 1) A power source. (cell, battery or mains power). 2) Components that have to do something (for example a motor, light bulb, speaker). 3) Conducting wires that connect all the parts in the circuit.

Circuit diagrams (Copy) Electrical symbols Cell Battery Switch - closed Switch - open

Connecting wires Light bulb Buzzer Motors

You have 5min to do this assessment Class assessment (on an extra piece of paper) You have 5min to do this assessment Draw the electrical symbol for: An open switch A motor 2) Label the following symbols: a) b) 3) Draw a closed circuit with a battery that has 2 cells and a buzzer.

Class assessment MEMO b) 2) a) Light bulb b) Cell

3) Draw a closed circuit with a battery that has 2 cells and a buzzer.

Homework: NS: Watch video: circuit diagrams.

Cell Battery

How to draw a circuit diagram: The output device is drawn opposite the input device. Input device : Output device : The process device is drawn between the input and output devices. Process device: If the switch is closed the direction of the current can be indicated with an arrow on the diagram. Electrical current always flows from positive to negative, through the circuit. Cell or battery Light bulb or motors Switch

4) 5) Buzzer Closed switch Battery

Conductors and Insulators A material that allows electricity to flow through it. Insulator A material that does not allow electricity to flow through it.

Discussion on figure 1 Discuss this picture by making reference to what you know about electrical safety and what you have learned about conductors and insulators.

Identify if the following items are conductors or insulators (Copy) Iron key, plastic ruler, loomy band, copper wire, metallic screwdriver, piece of paper, silver coin and a cloth. Conductors Insulators Iron key Plastic ruler Copper wire Loomy band Metallic screwdriver Piece of paper Silver coin Cloth Conductors Insulators

Homework: NS: Draw a mindmap