On the basis of kinetic theory of gases, the gas exerts pressure because its molecules:
- (A)Continuously lose their energy till it reaches wall.
- (B)Suffer change in momentum when impinge on the walls of container.✓ Correct
- (C)Are attracted by the walls of container.
- (D)Continuously stick to the walls of container.
Answer: (B)
Solution
A molecule that strikes a wall rebounds, and the component of its momentum normal to the wall is reversed. The wall supplies this change of momentum, and by Newton's third law the molecule pushes back on the wall with an equal and opposite impulse. Adding the momentum delivered by all such collisions in unit time over unit area gives a steady force per unit area. The gas exerts pressure because its molecules suffer a change in momentum when they impinge on the walls of the container.
JEE Main · 2021 · 24 Feb 2021 · Shift 2 · Single correct option