IC engines (SI/petrol): typical compression ratio range For conventional petrol (spark-ignition) engines, select the typical compression ratio range used in practice. Choose the correct range.
Mechanical Engineering
Thermodynamics
Difficulty: Easy
Choose an option
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A3 to 6
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B5 to 8
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C15 to 20
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D20 to 30
Answer
Correct Answer: 5 to 8
Explanation
ConceptSI (petrol) engines commonly operate with compression ratios ≈ 6:1–10:1. Among the given ranges, 5 to 8 best fits standard textbook values and avoids knock for regular fuels.
Final Answer5 to 8