Question

A thermally insulated container is divided into two parts by a screen. In one part the pressure and temperature are `P` and `T` for an ideal gas filled. In the second part it is vacuum. If now a small hole is created in the screen, then the temperature of the gas will
A. decrease
B. increase
C. remain same
D. none of these

Answer 1

Correct Answer - C
c. In second part time is a vacuum, i.e., `P = 0`. So wor done in expansion `= P Delta V = 0`. Also , `Delta Q = 0`. From the first law of thermodynamics, `Delta U = 0` i., temperature of an ideal gas remains same due to free expansion.