Efficiency, Wasted Energy and Insulation: Worked Examples | GCSE Physics

Efficiency for GCSE Physics, animated: why energy is never used up, where the wasted energy goes when it's dissipated into the surroundings, and how to read an energy-transfer diagram. Then efficiency = useful output ÷ total input as a decimal and a percentage, with worked examples line by line: a motor (70%), a kettle (85%), rearranging to find the energy supplied and the energy wasted, and the power version (AQA only) for an LED lamp (40%). How lubrication and thermal insulation cut unwanted energy transfers, what thermal conductivity means for how fast a house cools (thicker walls, lower conductivity, loft and cavity wall insulation, double glazing), the Higher tier ways to increase efficiency, and four mistakes that cost marks. Covers: AQA 4.1.2.1–4.1.2.2 (Combined 6.1.2) · Edexcel 3.7–3.12, 8.10, 8.11, 8.15, 9.10, 14.10 · OCR Gateway P7.2a–g (Combined P5.2). Combined Science and separate Physics; increasing efficiency is Higher tier on all three boards. 0:00 Intro 0:08 Hook 0:44 Where the energy goes 1:31 Efficiency 2:28 Worked examples 3:08 Worked example: find the input 4:01 Efficiency with power: AQA only 4:38 Wasting less 5:14 Thermal conductivity and homes 6:07 Higher tier: increasing efficiency 6:40 Common mistakes 7:13 Summary Narrated with an AI voice. Worked Example is not affiliated with or endorsed by AQA, OCR or Pearson Edexcel. Exam board names are used only to show which specifications a video covers.