Given below are two statements:
Statement I : Pressure of fluid is exerted only on a solid surface in contact as the fluid-pressure does not exist everywhere in a still fluid.
Statement II : Excess potential energy of the molecules on the surface of a liquid, when compared to interior, results in surface tension.
In the light of the above statements, choose the correct answer from the options given below.
- A
Statement I is true but Statement II is false
- B
Both Statement I and Statement II are false
- C
Both Statement I and Statement II are true
- D
Statement I is false but Statement II is true
Statement I — by Pascal’s law, pressure at any point in a fluid at rest exists in all directions and at every point in the fluid, not just at solid boundaries. Statement I is false.
Statement II — a molecule in the interior of a liquid feels symmetric attractions in every direction; a molecule at the surface feels only inward and sideways attractions. This asymmetry raises its potential energy relative to the bulk, and that excess surface energy per unit area is exactly the surface tension. True.
Practice more Physics
Concept-wise practice with instant solutions on Fundamenthol.
Start practicing →