Free First Law of Thermodynamics MCQs with Answers
11 First Law of Thermodynamics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
11 questions · page 2 of 2
11. According to first law of thermodynamics, when heat flows into a system and no work is done the internal energy of the system must
- A. Increase
- B. Decrease
- C. Remain constant
- D. Become zero
Explanation: The first law states that the change in internal energy equals the heat added plus the work done on the system, so with no work term every joule of heat entering raises the internal energy and the temperature rises. This is the constant volume case, which is why the molar specific heat at constant volume is smaller than at constant pressure. If the gas were allowed to expand, part of the heat would be spent doing work instead.
Correct answer: Increase