The tendency of a liquid drop to contract and occupy minimum area is due to

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Q: 106 (IAS/1997)
The tendency of a liquid drop to contract and occupy minimum area is due to

question_subject: 

Science

question_exam: 

IAS

stats: 

0,52,16,8,52,5,3

keywords: 

{'liquid drop': [0, 1, 0, 0], 'viscosity': [0, 0, 1, 0], 'surface tension': [0, 0, 2, 3], 'vapour pressure': [0, 0, 0, 1], 'minimum area': [0, 1, 1, 1], 'density': [2, 0, 1, 3], 'tendency': [0, 1, 1, 1]}

Option-1: Viscosity is a measure of a liquid`s resistance to flow. It does not influence a liquid drop`s tendency to contract and occupy minimum area.

Option-2: Surface tension is the correct answer. It is the force that makes liquid particles at the surface to contract towards the interior. This force brings the particles as close as possible, causing a liquid drop to take a shape that has the minimum surface area (a sphere).

Option-3: Density is the mass of a substance per unit volume. It only determines how heavy a substance is compared to the same volume of another substance but does not affect a liquid drop`s tendency to contract and occupy minimum area.

Option-4: Vapour pressure is the pressure exerted by the vapour in equilibrium with its liquid or solid phase at a given temperature. It doesn`t have a direct role in the contraction of a liquid drop.

In conclusion, the surface tension of a liquid will cause the liquid drop to contract and occupy the minimum area (approximating a spherical shape in a vacuum or in zero gravity) to achieve the lowest possible energy state.