Free Expansion
For ideal gas free expansion into vacuum: work and internal energy change are:
Select the correct option:
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
More thermodynamics Practice Questions
A gas is taken around a complete thermodynamic cycle and returns to its original state after several...
A gas is taken around a complete thermodynamic cycle and returns to its original state after several...
When 2 moles of a monatomic ideal gas are heated at constant pressure causing a temperature rise of ...
When 2 moles of a monatomic ideal gas are heated at constant pressure causing a temperature rise of ...
A heat pump uses 200 J of work to deliver a total of 800 J of heat into a warm room during each oper...
A heat pump uses 200 J of work to deliver a total of 800 J of heat into a warm room during each oper...
A balloon suddenly bursts and the compressed gas inside rushes out into the open atmosphere very rap...
A balloon suddenly bursts and the compressed gas inside rushes out into the open atmosphere very rap...
Two identical samples of the same ideal gas are kept at the same temperature but stored at very diff...
Two identical samples of the same ideal gas are kept at the same temperature but stored at very diff...
Two moles of an ideal gas expand isothermally at 300 K from a volume V to a volume 2V in a slow reve...
Two moles of an ideal gas expand isothermally at 300 K from a volume V to a volume 2V in a slow reve...
On a pressure-volume diagram an isothermal curve and an adiabatic curve pass through the same point ...
On a pressure-volume diagram an isothermal curve and an adiabatic curve pass through the same point ...
For a diatomic ideal gas the molar specific heat at constant volume is 5R/2, so what is the value of...
For a diatomic ideal gas the molar specific heat at constant volume is 5R/2, so what is the value of...
An ideal gas expands at a constant pressure of 2 × 10^5 Pa, increasing its volume from 0.01 m^3 to 0...
An ideal gas expands at a constant pressure of 2 × 10^5 Pa, increasing its volume from 0.01 m^3 to 0...
A heat engine absorbs 1000 J of heat from a hot reservoir and rejects 600 J to the cold reservoir in...
A heat engine absorbs 1000 J of heat from a hot reservoir and rejects 600 J to the cold reservoir in...
Heat of 400 J is supplied to a gas sealed inside a rigid steel container whose volume cannot change,...
Heat of 400 J is supplied to a gas sealed inside a rigid steel container whose volume cannot change,...
A monatomic ideal gas with gamma equal to 5/3 expands adiabatically until its volume becomes 8 times...
A monatomic ideal gas with gamma equal to 5/3 expands adiabatically until its volume becomes 8 times...
About This Question
- Subject
- physics
- Chapter
- thermodynamics
- Topic
- free expansion
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
Zero work, ΔU=0
Free expansion (Joule expansion) occurs when a gas expands into a vacuum through a valve.
- Work: Since there is no external pressure (Pext=0) for the gas to push against, the work done is zero (W=0).
- Heat: The container is typically insulated, so Q=0.
- Internal Energy: From First Law ΔU=Q−W=0−0=0. For an ideal gas, since U is purely a function of temperature (T), ΔU=0 implies the temperature of the gas remains constant (Ti=Tf).
This medium difficulty physics question is from the chapter thermodynamics, covering the topic of free expansion. It appeared in the 2025 exam.
Looking for more practice? Explore all physics questions or browse thermodynamics questions on RankGuru.