During adiabatic expansion the exchange in internal energy of 2 moles of a gas is -100J, the work done during the expansion is:
Correct answer: D. 100J
- A. Zero
- B. -100J
- C. 200J
- D. 100J
Explanation
During adiabatic expansion, there is no exchange of heat between the system and its surroundings. This means that the change in internal energy (ΔU) is solely due to the work done on or by the system. The first law of thermodynamics states: ΔU = Q - W Where: ΔU = Change in internal energy Q = Heat added to the system W = Work done by the system In this case, since the expansion is adiabatic (no heat exchange), the equation simplifies to: ΔU = -W -100J = - W (negative signs cancel out) W = 100J
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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
719 free Thermodynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More First Law of Thermodynamics questions
A gas expands 0.25 m3 at a constant pressure of 103 N/m2. The work done is:
The change in internal energy can be defined as:
Heat energy added to a system under isothermal conditions appears as:
Which of the following is necessarily zero when the system is a ideal gas that undergoes a change at a constant temperature?
The temperature of the system decreses in the process of:
Internal energy is a function of a state because change in internal energy: