JEE Main Physics · Thermodynamics

First Law of Thermodynamics in JEE Main

Name: First Law of Thermodynamics: JEE Main previous year questions
Creator: Lumi

First Law of Thermodynamics (Physics, Thermodynamics) came 18 times in 16 of the 42 JEE Main shifts Lumi analysed, across 13 distinct ideas. 11 of them came in 2024–26; it was last asked in 2026.

Questions: 18; in 16 shifts
Ideas asked: 13; 5 asked more than once
Numerical answer: 4; 22% of its questions
Pattern: Asked most years; last asked 2026

Questions each year

In the shifts Lumi analysed for each year.

Difficulty and format

Easy 8Medium 9Hard 1

Format

Single correct12 Q
Numerical value4 Q
Other1 Q
Diagram based1 Q

Ideas inside the topic

13 ideas

Adiabatic P-V Relation2 Q
First Law Energy Balance2 Q
Internal Energy Calculation2 Q
Heat in Isochoric and Isobaric Processes2 Q
Mayer's Relation (Cp and Cv)2 Q
Adiabatic T-V Relation1 Q
Work and Internal Energy in Adiabatic Processes1 Q
Adiabatic Work Formula1 Q
Isothermal Bulk Modulus1 Q
Work and Heat in Isothermal Processes1 Q
First Law in Phase Transitions1 Q
Work Done from P-V Graph Area1 Q

Where it sits

Part of Thermodynamics, which had 48 questions in all. First Law of Thermodynamics accounts for 38% of them. In Lumi's JEE taxonomy it belongs to Thermodynamics.

Some questions sit in other chapters too: Thermodynamics (Chemistry).

Every question

All 18 First Law of Thermodynamics questions

Newest first, each with its options and official answer.

2 Apr 2026, Shift 1 · Q47A vessel contains $0.15\ \mathrm{m^3}$ of a gas at pressure $8$ bar and temperature $140\ ^\circ$ C with $c_p=3R$ and $c_v=2R$ . It is…MediumNumerical value
2 Apr 2026, Shift 2 · Q485 moles of unknown gas is heated at constant volume from 10°C to 20°C. The molar specific heat of this gas at constant pressure $c_p = 8$ …MediumNumerical value
5 Apr 2026, Shift 1 · Q33Consider the following statements: A. Zeroth law of thermodynamics gives concept of temperature B. First law of thermodynamics gives…MediumOther
6 Apr 2026, Shift 1 · Q50A certain gas is isothermally compressed to $\left(\frac{1}{3}\right)^{\mathrm{rd}}$ of its initial volume ( $V_0=3$ litre) by applying…MediumNumerical value
6 Apr 2026, Shift 2 · Q35If 2 mole of an ideal monoatomic gas at temperature $T$ , is mixed with 6 mole of another ideal monoatomic gas at temperature $2T$ then the…EasySingle correct
8 Apr 2026, Shift 2 · Q35One mole of diatomic gas having rotational modes only is kept in a cylinder with a piston system. The cross-section area of the cylinder…MediumSingle correct
8 Apr 2026, Shift 2 · Q36Initial pressure and volume of a monoatomic ideal gas are $P$ and $V$ . The change in internal energy of this gas in adiabatic expansion to…MediumSingle correct
3 Apr 2025, Shift 1 · Q34A gas is kept in a container having walls which are thermally non-conducting. Initially the gas has a volume of $800\ \mathrm{cm^3}$ and…EasySingle correct
3 Apr 2025, Shift 1 · Q35A piston of mass M is hung from a massless spring whose restoring force law goes as $F = -kx^3$ , where k is the spring constant of…HardDiagram basedHas a figure
6 Apr 2024, Shift 2 · Q39A total of 48 J heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by $2^\circ\mathrm{C}$ . The…EasySingle correct
8 Apr 2024, Shift 1 · Q37Two different adiabatic paths for the same gas intersect two isothermal curves as shown in P-V diagram. The relation between the ratio…MediumSingle correctHas a figure
6 Apr 2023, Shift 1 · Q44A source supplies heat to a system at the rate of 1000 W. If the system performs work at a rate of 200 W. The rate at which internal…EasySingle correct
11 Apr 2023, Shift 1 · Q441 kg of water at $100^\circ$ C is converted into steam at $100^\circ$ C by boiling at atmospheric pressure. The volume of water changes from…MediumSingle correct
13 Apr 2023, Shift 2 · Q38The initial pressure and volume of an ideal gas are $P_0$ and $V_0$ . The final pressure of the gas when the gas is suddenly compressed to…EasySingle correct
29 Jun 2022, Shift 1 · Q35A cylinder of fixed capacity of 44.8 litres contains helium gas at standard temperature and pressure. The amount of heat needed to raise…EasySingle correct
3 Aug 2021, Shift 2 · Q3One mole Argon gas is sealed inside a thermally isolated chamber of 1 litre. A 100 W heater kept inside the chamber is switched on for 30…MediumSingle correct
8 Jan 2020, Shift 1 · Q47The magnitude of work done by a gas that undergoes a reversible expansion along the path ABC shown in the figure is ______.EasyNumerical valueHas a figure
2 Apr 2017 (offline) · Q10 $C_p$ and $C_v$ are specific heats at constant pressure and constant volume respectively. It is observed that $C_p - C_v = a$ for hydrogen…EasySingle correct