• Watch this video first.

Introducing Electricity – Part

1

• To draw and interpret circuit diagrams with a variety of electrical components

Learning outcomes:Learning outcomes:

You will learn:

2 main sources:

1. Mains electricity

2. Electric cells

- 2 or more cells make up a ‘battery’

Sources of electricitySources of electricity

Cross section of a torch

switch

Form a circuit for electricity to flow through

• Cells (Batteries)

• Bulb

• Switch

• Copper strips (Wires)

Examples of electrical components

What is a circuit?

• A circuit is the pathway through which current travels.

Spot the differences

A B

Open circuit

• When the switch is “off”, the circuit is open.

• Current cannot flow through it. The bulb will not be lit.

Open Circuit

Closed circuit

• When the switch is “on”, the circuit is closed.

• Current can flow through it. The bulb will be lit.

1. A source of electrical energy

2. A closed circuit

Conditions for the flow of an electric currentConditions for the flow of an electric current

Analysing

Look at the four circuits below.

1. In which circuit does the bulb light up?

Circuit D

• An easy way to represent the electrical components in a circuit

• Symbols are used to represent the various components

Circuit DiagramCircuit Diagram

Analysing, explaining

Here are two circuit diagrams with 2 light bulbs.

Which circuit, A or B, is the same as Circuit 2 seen in the previous slide? Explain.

Analysing, explaining

Circuit diagram A is the same as for Circuit 1 in Fig. E4.6. (The extra line between the two cells is unnecessary but not wrong). Circuit B is different as the light bulb is situated between the two cells.

Symbols of some electrical componentsSymbols of some electrical components

Visit the following website to build electric circuits and draw diagrams:

www.bbc.co.uk/schools/scienceclips/ages/10_11/changing_circuits.shtml

What have we learnt today

1. An electrical circuit is the path along which electrical charges move.

2.Batteries, bulbs, wires and switches are some electrical components that make up a circuit.

3.An open circuit cannot allow current to follow through it. A closed circuit allows current to flow through it.

4.You have learnt some symbols of the common electrical components that make up a circuit.