Question 93 of 192
Given below are two statements:
Statement I: Pressure of a 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
Show answer and solution
Answer: (A) Statement I is false but Statement II is true
Statement I is false: Fluid pressure exists everywhere in a still fluid, not only on solid surfaces. According to Pascal's principle, pressure at any point in a static fluid acts equally in all directions and throughout the fluid volume.
Statement II is true: Surface tension results from excess potential energy of molecules at the liquid surface. Surface molecules experience net inward attractive forces from interior molecules, creating an imbalance that increases their potential energy and manifests as surface tension acting along the surface.
Statement II is true: Surface tension results from excess potential energy of molecules at the liquid surface. Surface molecules experience net inward attractive forces from interior molecules, creating an imbalance that increases their potential energy and manifests as surface tension acting along the surface.