Efficiency
A machine lifts a load of 500 N through a height of 10 m in 25 seconds. If the power input is 400 W, what is the efficiency?
Select the correct option:
Solution
50%
- Output Work: Wout=Force×Distance=500 N×10 m=5000 J.
- Output Power: Pout=Wout/Time=5000/25=200 W.
- Efficiency Definition: η=Power InputPower Output×100%.
- Calculation:
- η=(200/400)×100=0.5×100.
- Result: Efficiency is 50%.
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About This Question
- Subject
- physics
- Chapter
- work, energy and power
- Topic
- efficiency
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
50%
- Output Work: Wout=Force×Distance=500 N×10 m=5000 J.
- Output Power: Pout=Wout/Time=5000/25=200 W.
- Efficiency Definition: η=Power InputPower Output×100%.
- Calculation:
- η=(200/400)×100=0.5×100.
- Result: Efficiency is 50%.
This medium difficulty physics question is from the chapter work, energy and power, covering the topic of efficiency. It appeared in the 2025 exam.
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