Question

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

• A. Both Statement I and Statement II are false
• B. Statement I is true but Statement II is false
• C. Both Statement I and Statement II are true
• D. Statement I is false but Statement II is true

Hint:

Fluid pressure exists at every point inside a fluid, while surface tension originates from unbalanced intermolecular forces at the liquid surface.

Answer 1

The Correct Option is A

Statement Analysis:

• 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.

Explanation: In a still fluid, pressure is exerted in all directions at any given point within the fluid. This means pressure is not only exerted on solid surfaces but also acts within every part of the fluid itself. Hence, this statement is false.

• Statement II: Excess potential energy of the molecules on the surface of a liquid, when compared to interior, results in surface tension.

Explanation: This statement is true. Surface tension arises because molecules at the surface experience a net inward force due to unbalanced intermolecular forces, which gives them higher potential energy compared to molecules in the interior. Therefore, excess potential energy results in the phenomenon known as surface tension.

Conclusion: Given the analyses above, Statement I is false, and Statement II is true. Therefore, the actual correct option is "Statement I is false but Statement II is true."