Physics · Class 11 · Thermodynamics

Thermodynamics for JEE

Everything you need for this topic on one page: the ideas, the formulas, the traps, and free lectures that explain it well.

Last updated: 26 October 2026

Direct answer

The first law, internal energy, work in different processes, specific heats, the second law, heat engines and refrigerators.

Key ideas

Thermodynamics: what you must understand

First law: Q = ΔU + W (W = work done by the gas)
Internal energy of an ideal gas depends only on temperature
Work = area under the P–V curve
No engine is more efficient than a Carnot engine between the same temperatures

Formula sheet

Must-know formulas for Thermodynamics

Isothermal: W = nRT ln(V₂/V₁)
Adiabatic: PVᵞ = constant, W = (P₁V₁ − P₂V₂)/(γ − 1)
Cₚ − Cᵥ = R
Carnot efficiency η = 1 − T₂/T₁

One-page formula sheet

Printable Thermodynamics formula sheet: formulas, key ideas and traps on one page. Save it as a PDF for offline revision.

Avoid

Common mistakes students make

Sign convention mix-up between physics (W by gas) and chemistry books
Using Celsius instead of kelvin in efficiency
Forgetting ΔU = 0 only for a complete cycle or isothermal ideal gas

For the exam

How this topic is asked in JEE

Appears frequently. P–V graph questions and cyclic processes are common. Calculate work as area, with sign from direction.

NCERT map

Where Thermodynamics is in NCERT

Chapter names follow the current rationalised NCERT textbooks. Read these sections before solving PYQs.

Class	Book	Chapter	Sections JEE asks from
Class 11	Physics Part II	Thermodynamics	First Law of Thermodynamics; Specific Heat Capacity; Thermodynamic State Variables and Equation of State; Heat Engines; Second Law of Thermodynamics

Free lectures

Best free lectures for Thermodynamics

Full-chapter free lectures picked from YouTube search results by views, from established JEE channels (mostly in Hinglish). Use the subtopic list to jump straight to the part you need (timestamps come from each video's own chapter list). Watch one, then solve PYQs the same day.

THERMODYNAMICS in One Shot: All Concepts & PYQs Covered | JEE Main & Advanced — JEE Wallah, 7:13:12
Jump to a subtopic (37)
- 00:00 Introduction
- 06:10 Important terms of thermodynamics
- 10:45 Types of system
- 16:07 Zeroth law of thermodynamics
- 17:43 Extensive and Intensive properties
- 38:40 State of the system
- 41:32 State & Path functions
- 49:20 Thermodynamic processes
- 1:04:50 Heat
- 1:07:17 Work done
- 1:22:05 Sign convention
- 1:24:14 First law of thermodynamics
- 1:37:34 Heat Capacity
- 2:11:50 Poisson’s ratio
- 2:20:29 Reversible process
- 2:28:00 Work done for isothermal process
- 2:47:12 Irreversible processes
- 2:56:59 Work done by gas in isothermal process
- 3:12:19 Adiabatic process
- 3:33:35 Isothermal & Adiabatic P-V graph slope
- 3:53:32 Molar heat capacity of gaseous mixture
- 4:05:20 Break
- 4:28:48 Thermochemistry - Heat
- 4:39:35 Heat of combustion
- 4:46:40 Heat of solution
- 4:49:16 Heat of dilution
- 5:25:23 Enthalpy of phase transition
- 5:32:26 Bond energies
- 5:43:32 Hess’s law
- 5:45:53 Born-haber cycle
- 6:01:38 Limitations of 1st law of thermodynamics
- 6:15:17 Net Entropy
- 6:36:20 Formulas
- 6:43:00 Adiabatic rule
- 6:50:50 Gibbs free energy
- 7:02:15 Bomb Calorimeter
- 7:12:12 Thank you bachhon
THERMODYNAMICS in ONE SHOT | All Concepts & PYQs Covered | Basic to Advanced | Class 11 JEE — PW JEE, 11:56:52
Jump to a subtopic (33)
- 00:00 Introduction
- 01:25 Parts of Thermodynamics
- 04:05 Terms Related to Thermodynamics
- 05:30 Boundary
- 13:12 Types of System
- 17:34 Extensive and Intensive Properties
- 40:20 State of the System
- 51:10 Thermodynamic Process (Isothermal, Isochoric, Isobaric, Cyclic & Adiabatic)
- 01:30:45 Internal Energy
- 01:53:45 Heat
- 01:56:10 Mathematical Expression of Work
- 02:14:16 First Law of Thermodynamics
- 02:57:36 Heat Capacity
- 03:26:00 Relation between Cp and Cv & Poisson's Ratio
- 03:45:45 Thermodynamics changes in Isothermal process
- 04:35:27 Adiabatic process
- 05:50:55 Thermochemistry
- 05:56:16 Heat of Reaction
- 06:14:35 Heat of Formation
- 06:47:00 Enthalpy or Heat of Combustion
- 07:12:58 Enthalpy or Heat of Solution & Dilution
- 07:40:10 Acid Base Reactions
- 08:03:30 Enthalpy of phase Transition
- 08:11:30 Hess's Law
- 09:02:38 Determination of Resonance Energy
- 09:10:40 Born Haber Cycle
- 09:32:05 Limitations of First law
- 09:34:40 Proposed criteria for spontaneity
- 09:41:50 Second Law of Thermodynamics
- 10:05:00 Quantitative Estimation of Enthalpy
- 11:18:00 Gibb's Energy
- 11:43:22 Bomb Calorimeter
- 11:56:30 Thank you

Practise

Where to practise for free

10 JEE Main 2026 PYQs on Thermodynamics, with solutions.
Read the chapter in NCERT textbooks (official, free), then solve its NCERT Exemplar (official, free) questions.
Chapter-wise past questions: JEE Main and Advanced PYQs and question bank.
Timed practice tests: NTA Abhyas practice tests (official, free) and our free mock tests.
See it move: interactive simulation.

FAQs

Frequently asked questions

Is Thermodynamics important for JEE Main 2027?

Appears frequently. It is part of the official 'Thermodynamics' unit in the JEE Main 2027 syllabus.

What are the most important formulas in Thermodynamics?

Isothermal: W = nRT ln(V₂/V₁); Adiabatic: PVᵞ = constant, W = (P₁V₁ − P₂V₂)/(γ − 1); Cₚ − Cᵥ = R.

How should I study Thermodynamics for JEE?

Understand the key ideas from NCERT or one full lecture, learn the formula sheet, then solve 25–30 past JEE questions on the topic. P–V graph questions and cyclic processes are common. Calculate work as area, with sign from direction.