Free physics question bank
cyclic process its effeciency ,second law of thermodynamics questions with solutions
Practice Thermodyanmics for JEE Main, JEE Advanced, NEET, and Classes 11–12. Attempt each question, then open it for the full solution.
Showing 1–9 of 9 questions
- MCQmediumThermodyanmics
The temperature of a body of mass m and specific heat capacity s is raised slowly from T₁ to T₂. The entropy change of the body is:
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JEE Mains 2025 23 Jan Evening Shift
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η₁, η₂ and η₃ are efficiencies of Carnot engines operating respectively between 473 K–273 K, 473 K–373 K and 373 K–273 K. Choose the correct relation.
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JEE Mains 2025 28 Jan Morning Shift
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An ideal gas initially has pressure P₀ and volume V₀. It is isothermally expanded to 4V₀, then isobarically compressed back to V₀, and finally heated isochorically to return to its initial state. The net heat exchanged in the complete cyclic process is:
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JEE Mains 2025 3 April Evening Shift
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An engine operating between the boiling and freezing points of water will have:
1. efficiency more than 27%
2. efficiency less than a Carnot engine operating between the same temperatures
3. efficiency equal to 27%
4. efficiency less than 27% Choose the correct answer.Options
JEE Mains12 April 2023Shift 1Morning Shift
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Two different adiabatic paths for the same gas intersect two isothermal curves as shown in P-V diagram. The relation between the ratio Vₐ/Vd and the ratio Vᵦ/Vc is:
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JEE Mains 2024 08 Apr Morning Shift
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The heat absorbed by a system in going through the given cyclic process is:
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JEE Mains 2024 05 Apr Morning Shift
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As shown in the figure, five Carnot engines, each with efficiency η and same number of cycles per unit time, are operating between six heat reservoirs. The amount of heat released per cycle by one engine is completely absorbed by the next engine. Consider Q₀ to be the amount of heat absorbed per cycle by the first engine and W as the amount of total work done by all the engines per cycle, then the net efficiency of the system is found to be η(net) = W/Q₀ = 211/243. The value of η is:
JEE Advanced2026Paper 1
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A Carnot engine operates between two reservoirs with efficiency 1/3. When the temperature of the cold reservoir is raised by x, its efficiency decreases to 1/6. If the hot-reservoir temperature is 99°C, x is:
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JEE MainsJEE Advanced
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A Carnot engine with efficiency 50% takes heat from a source at 600 K. In order to increase the efficiency to 70%, keeping the temperature of sink same, the new temperature of the source will be:
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JEE Mains25 January 2023Morning Shift
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