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Otto cycle efficiency for a given compression ratio: compute the thermal efficiency. Given: Compression ratio r = 5.5 for an ideal Otto cycle with γ ≈ 1.4. Find the approximate thermal efficiency (percentage).

Q: Otto cycle efficiency for a given compression ratio: compute the thermal efficiency. Given: Compression ratio r = 5.5 for an ideal Otto cycle with γ ≈ 1.4. Find the approximate thermal efficiency (percentage).

Given data Compression ratio r = 5.5 Specific heat ratio γ ≈ 1.4 (air-standard) Formula ηOtto = 1 − 1/r(γ−1) Step-by-step calculation r(γ−1) = 5.50.4 ≈ 1.977η = 1 − 1/1.977 ≈ 1 − 0.5056 ≈ 0.494η ≈ 49.4% ≈ 50% Final Answer 50%.