GCSE Physics (9-1) - GCSE Physics - Efficiency | Energy & Power (2026/27 exams)

⭐️ Check out our website https://www.cognito.org/ ⭐️ *** WHAT'S COVERED *** 1. The concept of efficiency in energy transfers. * The difference between useful energy output and wasted energy. * Why devices are not 100% efficient. 2. How to calculate the efficiency of a device. * The formula for efficiency using energy input and useful energy output. * The formula for efficiency using power input and useful power output. * How to express efficiency as a decimal or a percentage. 3. Worked examples of efficiency calculations. * Comparing the efficiency of an incandescent bulb and an LED bulb. * Calculating the useful power output of a microwave given its efficiency. 4. Common mistakes and key principles related to efficiency. * How to spot an incorrect calculation (e.g., efficiency greater than 100%). * The link between efficiency and the conservation of energy. * An explanation of why devices producing heat can be considered 100% efficient. *** CHAPTERS *** 0:00 Introduction 0:34 Useful & Wasted Energy 1:15 How to Calculate Efficiency 1:42 Worked Example: Lamp Efficiency 3:15 Common Mistakes When Calculating Efficiency 3:52 Worked Example: Microwave Power Output 4:35 Waste Energy & 100% Efficiency *** PLAYLISTS *** https://youtube.com/playlist?list=PLidqqIGKox7VzYfPIVt8T09xOLNcolCe4&si=8JmDajxjtba6rdc3 https://youtube.com/playlist?list=PLidqqIGKox7UZ3mWhbHv2aA_1vnbsfRPq&si=q3hEKdA4v7kbfwMe https://youtube.com/playlist?list=PLidqqIGKox7XPh1QacLRiKto_UlnRIEVh&si=orIUwL3o2jOoiYjT https://youtube.com/playlist?list=PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g&si=DcihOwUkd9oWbbdp https://youtube.com/playlist?list=PLidqqIGKox7WeOKVGHxcd69kKqtwrKl8W&si=Y8MsO-FK948jnxpS https://youtube.com/playlist?list=PLidqqIGKox7UVC-8WC9djoeBzwxPeXph7&si=-7i5Iq7yOeJrhtu6 https://youtube.com/playlist?list=PLidqqIGKox7VKJD2WxRhoKaI6JGLVean8&si=NH_Q1ujhVgACM2FU #GCSE #Physics #study #revision #school #exam #AQA #OCR #Edexcel #IGCSE