Physics
Grade-9
Easy
Question
A device gives out 500 J of heat energy as useful work. Determine the energy supplied to it as input if its efficiency is 40%.
- 1000 J
- 1250 J
- 1500 J
- 2000 J
Hint:
- Efficiency (%) = (useful energy output ÷ energy input) × 100
The correct answer is: 1250 J
- Efficiency (%) = (useful energy output ÷ energy input) × 100
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