The efficiency of a petrol engine is:
Correct answer: B. 25-30%
- A. 10-25%
- B. 25-30%
- C. 30-40%
- D. 40-50%
Explanation
Due to thermodynamic limitations (like the Carnot cycle) and practical losses from friction and incomplete combustion, a typical real-world petrol (gasoline) engine has a thermal efficiency in the range of 25-30%.
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About Energy Losses and Efficiency
Efficiency compares useful output energy or power with the total input, usually expressed as a percentage. The topic covers energy losses through friction, heating, resistance and sound, along with power ratings and Sankey diagrams. Efficiency is not the same as conservation of energy, because lost energy is transferred rather than destroyed.
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