Efficiency: GCSE Physics Definition

Efficiency: GCSE Physics Definition

What is Efficiency?

In GCSE Physics, the efficiency of a system is a measure of the amount of useful and wasted energy in an energy transfer. It is defined as either the ratio of useful energy output to total energy input or the ratio of useful power output to total power input. A system with a high efficiency is one in which most of the energy transferred is useful. 

Efficiency is a ratio so has no units and can be expressed as a decimal or a percentage. Efficiency is calculated using one of the following relevant equations:

Efficiency Revision Resources to Ace Your Exams

Efficiency is covered in many of the GCSE Physics and Combined Science course revision notes. Once you are ready to test your knowledge you can use our specific exam practice questions on energy, such as these for AQA GCSE Physics. If you are ready for some general exam revision then you can use the past paper section, for example, the OCR GCSE Physics past papers.

Explore all the Save My Exams GCSE Physics resources