Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Specific Heat Capacities of Gases
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Specific Heat Capacities of Gases
As shown in the figure, a gas undergoes a process during which both...
As shown in the figure, a gas undergoes a process during which both its pressure and volume change. Let be the molar heat capacity for this process.

Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
From the given graph, as the process proceeds, both pressure () and volume () of the gas increase. Therefore, and .
According to the ideal gas equation, . Differentiating both sides, we get:
Since , and are all positive quantities, the change in temperature must also be positive ().
From the first law of thermodynamics:
For moles of gas, this can be written in terms of molar heat capacities as:
Dividing the entire equation by , we get the molar heat capacity for the process:
Since , , , and , the term is strictly positive.
Therefore, .
According to the ideal gas equation, . Differentiating both sides, we get:
Since , and are all positive quantities, the change in temperature must also be positive ().
From the first law of thermodynamics:
For moles of gas, this can be written in terms of molar heat capacities as:
Dividing the entire equation by , we get the molar heat capacity for the process:
Since , , , and , the term is strictly positive.
Therefore, .