Q. If a gas expands at constant temperature, it indicates that
A) Number of the molecules of gas increases
B) Kinetic energy of molecules decreases
C) Pressure of the gas increases
D) Kinetic energy of molecules remains the same
Explanation
[Solution from source] The average kinetic energy of gas molecules is (3/2)kT and depends only on temperature, so at constant temperature it stays the same. In an isothermal expansion the pressure actually falls (Boyle's law), and the number of molecules is fixed. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.