A-LevelPhysicsWork, energy and powerMay/June 2011Paper 1 Q181 Mark
An electric motor produces 120 W of useful mechanical output power. The efficiency of the motor is 60%. Which row is correct?
Aelectrical power input/W: 72, waste heat power output/W: 48
Belectrical power input/W: 192, waste heat power output/W: 72
Celectrical power input/W: 200, waste heat power output/W: 72
Delectrical power input/W: 200, waste heat power output/W: 80
✓ Correct Answer
The correct answer is D. This question tests the candidate's understanding of work, energy and power within the Physicssyllabus. The examiner's mark scheme requires...
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
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