3. Planning investigations
The Key Activity builds on the ideas of energy change and the need for complete circuits. In it, pupils work in small groups to explore one effect of electricity –electromagnetism. This type of activity encourages pupils to think about different scientific processes –planning, observing and recording. After the activity, pupils could think of uses for their electromagnets (see Resource 5: Electromagnets for ideas).
Case Study 3 shows how a teacher with very limited resources encouraged her pupils to think through the processes involved in an investigation like this.
Case Study 3: Investigating electromagnetism with limited resources
Mrs Popoola works in a rural school with little equipment. She likes doing practical demonstrations with her pupils and is always searching through broken devices in the village to find equipment to use with them.
One day, she took apart an old buzzer to use as an example of an electromagnet. She set it up on her table and gathered her pupils around her. She showed them that she was using electricity to make a magnet. She then asked them each to discuss with their partner ideas for how she could make the magnet stronger –what could she change? How could they measure the strength of the magnet?
After a few minutes, Mrs Popoola asked pupils to share their ideas and she recorded the different suggestions on the chalkboard. Some pupils thought that if she used more torch cell batteries the magnet would get stronger. Others suggested using a different material in the core. Other ideas included longer wire, more coils round the core and using two strands of wire. Mrs Popoola then asked pairs of pupils to come out and try one of the ideas. They recorded the results in a table on the board. The next pair tried a different idea, and so on, until they had tried all the ideas. Her pupils copied down the table with the results and then, working with their partner, tried to write a sentence to summarise what they had found out.
Mrs Popoola was very pleased with the way her class listened to each other but she realised that next time she needed to make sure that equal numbers of boys and girls came out to do the experimenting.
Key Activity: Investigating electromagnets
Gather your class around you and brainstorm the concept of ‘magnetism’. (See.) Where have they seen magnets being used? What sorts of substances are magnetic? Can we make magnets from electricity? This is called an ‘electromagnet’. Record their thoughts on the chalkboard or on large newsprint on the wall.
- Organise your class into small groups of between four and six pupils. Give each group: a steel pin; a working 1. 5V torch cell; some small pins or paperclips; and 50 cm of thin insulated copper wire.
- Tell the groups you are setting them a problem. They have to use the equipment to make an electromagnet that will pick up as many pins as possible. (See Key Resource: Using investigations in the classroom.)
- Encourage pupils to investigate how to make an electromagnet with the equipment.
- When they have solved the problem, ask pupils to draw a diagram to show their solution.