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Thermodynamics — JEE Physics MCQs

Master Thermodynamics for JEE Main with free physics MCQs. Each question includes a detailed solution and instant feedback — practice at easy, medium, and hard difficulty levels to build exam-ready confidence.

8 practice questions with instant feedback and solutions.

Medium•Thermodynamics
[JEE Mains 2026] For an ideal gas, the volume is made 8 times and temperature is decreased to 1/4 of its initial value during an adiabatic process (q = 0). What is the value of γ (ratio of specific heats) for this gas?
Easy•Thermodynamics
An ideal gas at 27°C27°C is heated at constant pressure to 327°C327°C. The ratio of final to initial volume is:
Hard•Thermodynamics
List I describes thermodynamic processes in four different systems. List II gives the magnitudes (either exactly or as a close approximation) of possible changes in the internal energy of the system due to the process. List-I (I) 10−3 kg10^{-3} \mathrm{~kg} of water at 100∘C100^{\circ} \mathrm{C} is converted to steam at the same temperature, at a pressure of 105 Pa10^5 \mathrm{~Pa}. The volume of the system changes from 10−6 m310^{-6} \mathrm{~m}^3 to 10−3 m310^{-3} \mathrm{~m}^3 in the process. Latent heat of water =2250 kJ/kg=2250 \mathrm{~kJ} / \mathrm{kg}. (II) 0.2 moles of a rigid diatomic ideal gas with volume VV at temperature 500 K500 \mathrm{~K} undergoes an isobaric expansion to volume 3 V3 \mathrm{~V}. Assume R=8.0 J mol−1 K−1R=8.0 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}. (III) One mole of a monatomic ideal gas is compressed adiabatically from volume V=13m3V=\frac{1}{3} m^3 and pressure 2kPa2 \mathrm{kPa} to volume V8\frac{V}{8}. (IV) Three moles of a diatomic ideal gas whose molecules can vibrate, is given 9 kJ9 \mathrm{~kJ} of heat and undergoes isobaric expansion. List-II (P) 2 kJ2 \mathrm{~kJ} (Q) 7 kJ7 \mathrm{~kJ} (R) 4 kJ4 \mathrm{~kJ} (S) 5 kJ5 \mathrm{~kJ} (T) 3 kJ3 \mathrm{~kJ} Which one of the following options is correct?\
Hard•Thermodynamics
A gas is enclosed in a cylinder with a movable frictionless piston. Its initial thermodynamic state at pressure Pi=105 PaP_{i}=10^{5} \mathrm{~Pa} and volume Vi=10−3 m3V_{i}=10^{-3} \mathrm{~m}^{3} changes to a final state at Pf=(1/32)×105 PaP_{f}=(1 / 32) \times 10^{5} \mathrm{~Pa} and Vf=8×10−3 m3V_{f}=8 \times 10^{-3} \mathrm{~m}^{3} in an adiabatic quasi-static process, such that P3V5=P^{3} V^{5}= constant. Consider another thermodynamic process that brings the system from the same initial state to the same final state in two steps: an isobaric expansion at PiP_{i} followed by an isochoric (isovolumetric) process at volume VfV_{f}. The amount of heat supplied to the system in the two-step process is approximately
Hard•Thermodynamics
One mole of an ideal gas expands adiabatically from an initial state (TA,V0)\left(T_{\mathrm{A}}, V_{0}\right) to final state (Tf,5V0)\left(T_{\mathrm{f}}, 5 V_{0}\right). Another mole of the same gas expands isothermally from a different initial state (TB,V0)\left(T_{\mathrm{B}}, V_{0}\right) to the same final state (Tf,5V0)\left(T_{\mathrm{f}}, 5 V_{0}\right). The ratio of the specific heats at constant pressure and constant volume of this ideal gas is γ\gamma. What is the ratio TA/TBT_{\mathrm{A}} / T_{\mathrm{B}} ?
Medium•Thermodynamics
An ideal gas expands isothermally from volume VV to 2V2V. If the same gas expands from volume VV to 2V2V adiabatically, then the work done in isothermal expansion is:
Medium•Thermodynamics
The ends Q\mathrm{Q} and R\mathrm{R} of two thin wires, PQ\mathrm{PQ} and RS, are soldered (joined) together. Initially each of the wires has a length of 1 m1 \mathrm{~m} at 10∘C10^{\circ} \mathrm{C}. Now the end PP is maintained at 10∘C10^{\circ} \mathrm{C}, while the end S\mathrm{S} is heated and maintained at 400∘C400^{\circ} \mathrm{C}. The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ\mathrm{PQ} is twice that of the wire RSR S and the coefficient of linear thermal expansion of PQ\mathrm{PQ} is 1.2×10−5 K−11.2 \times 10^{-5} \mathrm{~K}^{-1}, the change in length of the wire PQP Q is
Medium•Thermodynamics
An ideal gas is in thermodynamic equilibrium. The number of degrees of freedom of a molecule of the gas is nn. The internal energy of one mole of the gas is UnU_{n} and the speed of sound in the gas is vn\mathrm{v}_{n}. At a fixed temperature and pressure, which of the following is the correct option?