Q105 / 150 · MHT CET 2019 (Shift 1) · Physics

A molecule of water on the surface

A
Downward resultant unbalanced adhesive force
B
Upward resultant unbalanced cohesive force
Correct answer
C
Downward resultant unbalanced cohesive force
D
Upward resultant unbalanced adhesive force

Solution

A molecule on the surface experiences a net force (Cohesive force) in downward direction due to net number of molecules pulling it in the downward direction (molecule A as shown in figure underneath).
In contrast, a molecule well inside is equally pulled in all directions by molecules around at (molecule B as shown in figure)

Hence, the correct answer is option: 'C'.

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