Useful, wasted, and dissipated energy transfers
Useful, wasted, and dissipated energy transfers

In a system, energy is transferred between stores when a device works. Total energy is conserved, so energy is not "used up" or destroyed.
Step-by-step lessons on OCR GCSE Physics Power and efficiency. Each one builds up to exam-style questions. Paper 2 and Paper 4 include synoptic questions that draw on Topics P1–P4, so revisit earlier topics before final exams rather than treating each paper as self-contained.