Insulation: GCSE Physics Definition

What is insulation?

Insulation reduces the amount of unwanted energy transfers. In GCSE Physics, you need to know about two different uses of insulation:

• Thermal insulation reduces unwanted energy transfer by heating and is used to minimise heat loss

• Electrical insulation reduces unwanted energy transfer by electrical work and is used to ensure safety in electrical circuits

Thermal insulation

Materials, such as wool or fibreglass, are effective thermal insulators because they trap air, reducing energy transfer through conduction, convection, and radiation. The effectiveness of insulation depends on:

• the thermal conductivity of the material

  • The lower the thermal conductivity, the slower the rate of energy transfer and the more effective the material is at insulating

• the thickness of the material

  • The thicker the material, the slower the rate of energy transfer across the material and the more effective the material is at insulating

Electrical insulation

Electrical insulators, such as plastic, coat the metal wires in electrical circuits to prevent the unwanted flow of electric current, which reduces the risk of electrocution.

Insulation revision resources to ace your exams

You can strengthen your understanding of how thermal insulation can reduce unwanted energy transfers by using our revision notes tailored specifically for the AQA, Edexcel, OCR, and WJEC exam boards. Or you can learn more about electrical insulation in mains electricity in our revision notes for AQA, Edexcel, and OCR exam boards.

You can practice questions about insulation with helpful guidance and examiner tips using our exam board-specific GCSE Physics exam questions.

Explore our GCSE Physics Revision Resources