Q. A drop of oil is placed on the surface of water then it will spread as a thin layer because
A) surface tension tends to give the oil a spherical surface
B) surface tension of water is greater than that of oil
C) both oil and water have nearly equal surface tension
D) oil is lighter than water
Explanation
(b) An oil drop spreads as thin layer, on the surface of water because the cohesive force between water molecules is greater than the adhesive force between water-oil molecules, hence the surface tension of water is greater than that oil.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.