A diatomic ideal gas is used in a Carnot engine as the working substance. If during the adiabatic expansion part of the cycle, volume of the gas incre - Physics MCQ AIEEE 2026 | ExamTest.live

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A diatomic ideal gas is used in a Carnot engine as the working substance. If during the adiabatic expansion part of the cycle, volume of the gas increases from V to 32 V, the efficiency of the engine is:

Solution & Step-by-step Explanation

For a diatomic gas, γ = 7/5 = 1.4 .In an adiabatic process: T_{1} V_{1}^{γ - 1} = T_{2} V_{2}^{γ - 1} . \frac{T _{2}}{T _{1}} = (\frac{V _{1}}{V _{2}})^{γ - 1} = (\frac{V}{32 V})^{1.4 - 1} = (\frac{1}{32})^{0.4} 32 = 2^{5} ⟹ (\frac{1}{2 ^{5}})^{2/5} = \frac{1}{2 ^{2}} = \frac{1}{4} Efficiency η = 1 - \frac{T _{2}}{T _{1}} = 1 - \frac{1}{4} = 0.75 .

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A diatomic ideal gas is used in a Carnot engine as the working substance. If during the adiabatic expansion part of the cycle, volume of the gas increases from V to 32 V, the efficiency of the engine is:

0.5

0.75

0.99

0.25

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