Thermodynamics

JEE Main level, single correct, medium

4 of 190

Question 4 of 190

Consider the following statements:
A. Zeroth law of thermodynamics gives concept of temperature

B. First law of thermodynamics gives concept of internal energy

C. In isothermal expansion of ideal gas,
ΔQ≠ΔW\Delta Q \neq \Delta W
D. Product of intensive and extensive variables is extensive

E. The ratio of any extensive variable to mass will be an extensive variable

Choose the correct combination of statements from the options given below:

Show answer and solution

Answer: (C) A, B and D Only

Statement A is correct because the zeroth law of thermodynamics defines temperature and thermal equilibrium.

Statement B is correct because the first law of thermodynamics introduces the concept of internal energy through the equation
ΔQ=ΔU+ΔW\Delta Q = \Delta U + \Delta W.

Statement C is incorrect because for an isothermal expansion of an ideal gas, the change in internal energy
ΔU=0\Delta U = 0. According to the first law of thermodynamics, ΔQ=ΔW\Delta Q = \Delta W.

Statement D is correct because if an intensive variable (which is independent of the size of the system) is multiplied by an extensive variable (which is directly proportional to the size of the system), the product will be directly proportional to the size of the system, making it an extensive variable.


Statement E is incorrect because the ratio of two extensive variables (like any extensive variable and mass) is independent of the size of the system, making it an intensive variable.


Therefore, only statements A, B, and D are correct.


Answer: A, B and D Only

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Thermodynamics (Thermodynamic Systems), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.