Explore electrical resistance

Testing the electrical resistivity of different materials

In this activity learners will make use of the theme of electrical resistance to experiment with an electronic circuit. They will learn how to use an electronic multimeter and will then apply their skills to test the electrical resistivity of various materials.

This activity could be used as a main lesson activity to teach about resistors and their use. It could also be used as part of a wider scheme of learning focussing on the selection of materials for different applications.

This is one of a series of resources developed in association with the National Grid ESO, to allow learners to use the theme of electronics to develop their knowledge and skills in Design & Technology and Science. This resource focusses on practical experiments investigating the resistance of different materials. National Grid ESO ensure that Great Britain has the essential energy it needs by ensuring supply meets demand every second of every day.

The teacher will explain what is meant by resistance and then explain the task to the learners through a series of practical hands-on activities. At the end of the session the teacher will get the learners back together to discuss their findings.

This activity can be simplified (particularly for less able students) by setting up the multimeter in advance to the correct range before handing to learners.

This activity is designed to take between 45-70 minutes.

Tools/resources required

Multimeters (digital or analogue)
Assorted resistors, including 33kΩ
Breadboards
Crocodile clips
Pencils and paper
Glass of water
Table salt
Selection of materials (for the extension activity)

The engineering context

Many components, such as integrated circuits, can be damaged by high current. An understanding of resistance allows electrical engineers to select resistors to protect these components, ensuring the effective and continued operation of the electronic devices.

Suggested learning outcomes

By the end of this free resource students will be able to choose materials based on their resistivity; understand the basics of resistance; and be able to use electronic devices to measure resistance.

All activity sheets and supporting resources are free to download, and all the documents are fully editable, so you can tailor them to your students’ and your schools’ needs.

The activity sheet includes teacher notes, guidance, useful web links, and links (where appropriate) to the national curriculum in each of the four devolved UK nations; England, Northern Ireland, Scotland and Wales.

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