Thermodynamics and Statistical Mechanics · Laws of thermodynamics · 1 mark · Multiple choice
An insulated container has ideal gas in chamber A and vacuum in chamber B. A plug separating the chambers is removed and the gas fills both. Which statement is true?
Gas temperature remains unchanged.
Internal energy decreases.
Temperature decreases while the gas expands into B.
Internal energy increases because atoms have more room.
Correct answer: (A) Gas temperature remains unchanged.
Explanation
This is free expansion into vacuum. The insulated boundary gives Q = 0, and zero external opposing pressure gives W = 0. The first law therefore gives $\Delta U=0$. For an ideal gas, internal energy depends only on temperature, so $\Delta T=0$. Entropy increases even though the temperature stays unchanged. Select A.
More Laws of thermodynamics questions
GATE 2020 PH Q48– A system has internal energy U(S,V)= V-2/3S2, where λ is constant, V volume and S entropy.…
GATE 2024 PH Q14– If a thermodynamical system is adiabatically isolated and experiences a change in volume…
