Verified Solution • 2025–26 Session
moderate
QJEEAdv23Ph2e5a: JEE Advanced 2023 Physics - Class 11 JEEAdv23Ph2e5a Solution: An ideal gas is in thermodynamic equilibrium. The number of…
An ideal gas is in thermodynamic equilibrium. The number of degrees of freedom of a molecule of the gas is . The internal energy of one mole of the gas is and the speed of sound in the gas is . At a fixed temperature and pressure, which of the following is the correct option?
Multiple Choice Options
- A and
- B and
- C and
- D and
Step-by-Step Verified Solution
1. Formula for Sound Velocity:
- The velocity of sound, denoted as , is determined by the equation , where:
- is a factor given by .
- is the gas constant.
- is the temperature.
- is the molar mass of the gas.
2. Relation of with :
- The value of is inversely related to . This means as increases, decreases.
3. Internal Energy Relation:
- The internal energy, denoted as , for a mole of gas is given by .
4. Effect of Increasing on Sound Velocity and Internal Energy:
When the value of increases:
- The factor decreases, according to its formula.
- As a result, the velocity of sound also decreases, as it is dependent on .
- Conversely, the internal energy increases with the increase in , as evident from the internal energy formula.
- The velocity of sound, denoted as
-
-
-
-
2. Relation of
- The value of
3. Internal Energy Relation:
- The internal energy, denoted as
4. Effect of Increasing
When the value of
- The factor
- As a result, the velocity of sound
- Conversely, the internal energy
Therefore, in summary, a higher value of