Question

Two pieces of glass plate upon the other with a little water between them cannot be separated easily because of:
(A) Inertia
(B) Pressure
(C) Viscosity
(D) Surface tension

Answer 1

Hint: In order to solve this question, we should know the meaning of inertia, pressure, viscosity and surface tension. The property of the surface of a liquid which allows it to resist any external force because of the cohesive nature of the water molecules present is known as surface tension.

Complete answer:
In physics, inertia can be defined as the property of matter by which it remains at a state of rest or in uniform motion in the same straight line until and unless some external force acts upon it.

The perpendicular force per unit area or the stress at any particular point within a confined fluid is known as pressure.

In physics, viscosity can be defined as the resistance of a fluid which can be a gas or a liquid, to a change in the movement or the shape of the neighbouring portions relative to each other.

The cohesive forces between the liquid molecules are the reason for the difficulty of separation when two pieces of glass plate are placed upon the other with a little water between them.

therefore, two pieces of glass plate upon the other with a little water between them cannot be separated easily because of surface tension.

Therefore, Option D is the correct answer.

Note:Surface tension is responsible for creating the repulsive force when the glass plates with little water between them are tried to separate. In simple words, surface tension can be defined as a force which causes a layer of liquid to act as an elastic sheet or skin.