ELECTRICITY FOR YEAR 3 SCIENCE

3.3.1 Using Electricity

Learning Outcome

state that dry cells and the mains are the two main sources of electricity

Ask pupils what they know about electricity. Write down answers on the whiteboard.

The two main sources of electricity are as follows:

Mains

Cells/batteryTeachers may give hints or prompt to elicit responses from children.

After sources of electricity have been brought up for discussion, then discuss further into how mains electricity is produced. There are two main sources of electricity, namely:

1. Mains in the home:Elicit sources of energy that is used to produce electricity in power stations. Let children come up with their ideas although prompting may be necessary. Talk about energy sources from (a) petroleum/dieses/coal(use terms like ‘petrol’)(b) wind (c) sun (d) any other sources

Show video clip on sources of energy. As these are young children, there is no need to elaborate or explain exactly how electricity is produced. From the video clip, it is sufficient to note the following:

2. Battery/Cells

HOMES

Sent or transmitted to

Sources of energy e.g. petroleum/coal, wind, sun etc

ELECTRICITYUsed to produce

Show types of cells/batteries and how and where they are used or applied. Examples are: torchlight, radio, tape recorders, hand phones, etc.

Suggestion for assessment: Draw and/or name appliances that use mains electricity and appliances that use batteries.

Teachers may be able to discuss the advantages and disadvantages of using appliances that use mains electricity and appliances that use batteries with more able pupils.

Some typical answers are as follows:

Battery operated appliances are usually small, lighter and can be carried around easily.

Mains appliances are usually more powerful – no charging or replacement needed.

3.3.1 Using Electricity

Learning Outcome

identify some electrical appliances used everyday

Electrical appliances in the home

Elicit names of electrical appliances in the home. Make a list on the whiteboard. Then show PowerPoint slides of electrical appliances and ask pupils to name each appliance. This may serve as an avenue to assess pupils’ awareness and knowledge of electrical appliances used in the home.

3.3.1 Using Electricity

Learning Outcomes

connect two or more dry cells together to make up a battery

identify dry cell, battery, wire and light bulb

set up a simple electric circuit using dry cells, wires and light bulbs

Practical Activity

Pupils may have by now come across the electric cell as a source of electricity. In a torchlight, the cells light up the bulb. Challenge pupils to do the following activities.

Activity 1: Lighting up a bulb (1)

Provide pupils with the following: 1 light bulb

1 cell

1 wire

Use the cell, bulb and one wire to make a ’complete’ circuit to light up the bulb.

Teacher may give a hint if pupils find it difficult to get the right connection. Get pupils to sketch their circuit that will light up the bulb. Then get them to demonstrate and compare their circuits.

Note: Teacher may have to spend some time to explain what a ‘circuit’ is. At this juncture it is can be explained as ‘what goes around in a loop’. It is noted that pupils may have come across the word ‘complete’ in mathematics but teachers should relate it to an electric circuit.

Activity 2: Lighting up a bulb (2)Provide pupils with the following:

1 light bulb

1 cell

2 wires Straw board

Teacher may give a hint if some pupils find it difficult to make the right connection. Get pupils to sketch their circuit that will light up the bulb. Then get them to present and compare their circuits. There is probably more than one possible way to make the right connection to light up the bulb.

One way to carry out this activity is to provide pupils with a bulb and an electric cell (size D) stuck to a strawboard using blue tack (see diagram below).Then ask pupils to connect the two wires so that the bulb lights up. Then draw the circuit with the successful connection.

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Ask pupils if there are other ways to make a successful connection. Compare with other groups.

Use a blank template for pupils to draw the connection.

Activity 3: A cell and a batteryProvide pupils with the following:

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Straw board

Stick bulb (1.5 volt) onto strawboard using blue tack.

Stick cell (1.5 volt) onto strawboard using blue tack.

1 light bulb

2 cells

2 wires Straw board

Connect wires to make a circuit to light up the bulb.

Suggestion: Teacher could ask one group to set up a circuit using one cell, and another group using two cells (in series) as shown above. Emphasise that when two cells (or more) are joined together they make up a battery. The distinction between ‘cell’ and ‘battery’ must be made clear to avoid confusion or misconception later on. Draw the circuit. Then ask pupils to compare the brightness of each arrangement. Make a conclusion (if pupils are able).

Worksheet 1 Make a complete circuitStudy the pictures below and the answer the following questions.

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Stick bulb (2.5 volt) onto strawboard using blue tack.

Stick two 1.5 volt cells onto strawboard using blue tack.

Battery (3.0 volts)

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1. Draw a circle on the bulbs that will light up.

2. The bulb in a circuit will light up because the circuit is _____________________. (complete/not complete)

Worksheet 2 Making a circuit

Study the circuit given below.

B

DC

E

F

A

A circuit is a path that allows electricity to pass through it. For electricity to pass through the circuit must be a complete loop. Electricity flows from the negative terminal to the positive terminal of a cell.

Worksheet (2A) Making the circuit work

__

Wire

Cell

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Bulb

Circuit

Wires

(i) What are the components in this?

_______________________________________________________________________________________

(ii) Will electricity flow through this circuit?

Yes No

(iii) What is missing from this circuit to make it work?

____________________________________________________________________________________

(iv) Draw a diagram to complete the circuit that will allow the electricity to flow.

Worksheet (2B) Making the circuit work

(i) What are the components in this circuit?

Circuit

_________________________________________________(ii) Will electricity flow through this circuit?

Yes No

(iii) What is missing from this circuit to make it work? ___________________________________________________(iv) Draw a diagram to complete the circuit that will

allow the electricity to flow.

Worksheet (2C) Making the circuit work

(i) What are the components in this circuit?

__________________________________________________

(ii) Will electricity flow through this circuit?

Yes No

Circuit

(iii) What is missing from this circuit to make it work?

_________________________________________________

(iv) Draw a diagram to complete the circuit that will allow the electricity to flow.

Worksheet 3 Make a complete circuit

Use two cells arranged as shown. Use wires to join the cells and one or two bulbs to make a complete circuit.

Draw the arrangement in the box below.

Worksheet 4

Fill in the missing words

(i) A circuit is a _ _ _ _that allows _ _ _ _ _ _ _ _ _ _ _

to pass through it.

(ii) A circuit will only work if it is _ _ _ _ _ _ _ _.

This means it must make a complete _ _ _ _, otherwise

the electrical _ _ _ _ _ _ cannot flow.

path electricity complete

loop

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(iii) Draw arrows on the diagram to show which way round the electricity is flowing.

demonstrate that a bulb can be switched on and off by using a switch

Pupils should do an activity to use a simple switch in the electric circuit.

Pupils will then compare the simple switch with the switch used in the home.

SAFETY – Teacher should remind pupils not to play with the switches at home.