First Law of Thermodynamics and Sign Conventions
Master the first law of thermodynamics, including its mathematical form, sign conventions, and application to various processes.
Why this shows up in the exam
You must apply the first law correctly, especially with sign conventions, in both NEET and JEE problems.
How NEET tests this
Practise it
These are real questions from past NEET papers that test this exact idea.
At a certain temperature, T(K), during a process 500 J is absorbed by the system and work of 200 J is done by the system. Then change in internal energy of the system is
Push further
More challenging4 harder questions built from the past papers above — a step up in difficulty, with distractors designed so you can't get there by elimination. Written and checked by our reviewers, not from a real paper.
A gas is enclosed in a perfectly insulated cylinder fitted with a frictionless piston. If the piston is pushed inward rapidly, causing the gas to compress, which of the following statements correctly describes the changes in internal energy (ΔE), heat (q), and work (W)?
More from Thermodynamics
Thermodynamic Processes and P-V Diagrams
Study different thermodynamic processes (isothermal, isobaric, isochoric, adiabatic, polytropic, cyclic), their definitions, characteristics, and graphical representation on P-V diagrams.
Laws of Thermodynamics
Understand the zeroth and first laws of thermodynamics, including their statements, implications, and applications to physical systems.
Internal Energy, Heat, and Work
Explore the concepts of internal energy, heat, and work, including their definitions, relationships, and how they change during various thermodynamic processes.
Ideal Gas Law and Equation
Learn the ideal gas equation, its relation to physical quantities like pressure, volume, temperature, and density, and its use in describing the behavior of ideal gases.
Gibbs Free Energy and Spontaneity
Learn how Gibbs free energy determines spontaneity, how to calculate it, and its dependence on temperature, pressure, and other thermodynamic parameters.
Entropy and Its Changes
Understand entropy as a measure of disorder, how it changes in physical and chemical processes, and its calculation in various scenarios including phase transitions and isothermal processes.