Mechanical Physics MCQ question and answer with solution | Physics Gk MCQs

The correct answer is A: requires larger deforming force
Here's why:
Elasticity refers to a material's ability to return to its original shape after a force is applied and then removed.
A material is considered *more* elastic if it resists deformation more strongly.
Think of it this way:
Imagine stretching both a steel rod and a rubber band.
The steel rod needs much more force to stretch even a little bit.
The rubber band stretches easily with much less force.
Therefore, steel is more elastic because it requires a larger deforming force to change its shape.
Option B is incorrect: Steel can be deformed.
Option C is incorrect: Steel is not easily deformed.
Option D (hardness) is related to resistance to scratching or indentation, not elasticity (resistance to deformation and return to original shape).

The correct answer is A: adhesive force.
Let's break down why:

Adhesive force is the attraction between different types of molecules.
Think of it like glue! The chalk sticks to the blackboard because of this attraction.

Cohesive force is the attraction between the same type of molecules.
This is what holds the chalk together as a solid, not what makes it stick to the board.

Surface tension is the property of a liquid that makes its surface behave like a stretched membrane.
It's not really relevant to chalk and blackboards.

Viscosity is a fluid's resistance to flow.
Think of honey versus water. Again, not relevant here.

So, the adhesive force is the key property that allows the chalk to stick to the blackboard and leave a mark.