Internal energy of an ideal gas depends only on:
AIts volume
BIts temperature
CIts pressure
DIts density
Answer & Solution
Correct answer: B. Its temperature
1. For an ideal gas, molecules are point particles with no inter-molecular PE.
2. Internal energy is purely the kinetic energy of random thermal motion.
3. From kinetic theory, average KE per molecule = (f/2) k_B T, function of T only.
4. Hence U = U(T) for an ideal gas — independent of P and V.
_Source: NCERT Class 11 Physics Ch 11, §11.5 + Ch 12 Kinetic Theory_
Related questions
Which of the following is a reversible process in the thermodynamic sense?A refrigerator extracts 600 J from the cold compartment and rejects 800 J to the room. ItsFor an ideal gas the adiabatic equation linking pressure and volume is:A Carnot engine operates between 400 K and 300 K. If it absorbs 800 J from the hot reservoThe change in internal energy of an ideal gas (γ = 1.4) when 2 moles are heated from 300 KThe second law of thermodynamics can be stated as: no engine can convert into work:The Carnot engine's efficiency between source temperature T₁ (hot) and sink T₂ (cold) is:An ideal gas at temperature T₁ is expanded adiabatically. Its final temperature T₂ is: