Which one is true for internal energy ?
Correct answer: D. All are correct
- A. It is sum of all forms of energies associated with molecules of a system
- B. It is a state function of a system
- C. It is proportional to transnational K.E of the molecules
- D. All are correct
Explanation
Internal energy is the total microscopic energy of a system, including molecular kinetic and potential energies, and it is a state function because it depends only on the state, not the path taken. For an ideal gas, it is related to the molecules' average translational kinetic energy, so all the listed statements are accepted in this context. The likely alternative is a, chosen by overlooking the separate facts that internal energy is also a state function and temperature-related molecular kinetic energy.
Last updated
About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
Practise Thermodynamics
714 free Thermodynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
110 J of heat is added to a gaseous system, whose internal energy change is 40 J, then the amount of external work done is
1st law of thermodynamics is consequence of conservation of
A Carnot engine operates between reservoirs at 600 K and 300 K. Its maximum possible efficiency is
A carnot engine working between 200k and 400k has a work output of 600 J per cycle. How much heat energy is supplied to the engine from the source of each cycle.
A chemical system is sealed in a strong rigid container at room temp and then heated vigorously change in work done during the process is: