250+ TOP MCQs on Elastic Behaviour of Solids | Class 11 Physics

Physics Multiple Choice Questions on “Elastic Behaviour of Solids”.

1. A completely elastic solid body partially regains its shape after removal of external force. True or False?
a) True
b) False
Answer: b
Clarification: A solid body which partially regains its shape after complete removal of force is called partially elastic body. It is called completely elastic when it completely regains its shape.

2. A partially elastic body can never be permanently deformed. True or False?
a) True
b) False
Answer: b
Clarification: Only a completely elastic body can never be permanently deformed before breaking point. All partially elastic bodies regain a little shape and undergo some permanent deformation after yield point.

3. This is a diagram for which type of material?

a) Perfectly elastic
b) Partially elastic
c) Completely plastic
d) Perfectly rigid
Answer: a
Clarification: This diagram shows that stress is always proportional to strain until breaking point. So the body will regain its shape completely on removal of force. The fracture point is just after yield point so the body acts completely elastical until it breaks.

4. Select the correct order with regard to elasticity of materials.
a) Steel > Glass > Rubber
b) Glass > Rubber > Steel
c) Rubber > Glass > Steel
d) Rubber > Steel > Glass
Answer: a
Clarification: Elasticity is the property of a material to regain shape when deforming forces are removed. Out of the three, for the same stress, steel will show much less or maybe no permanent deformation as compared to glass which in turn will show less permanent deformation than rubber. Remember all this comparison is for the same amount of stress.

5. The forces responsible for a body regaining its shape after removal of deforming forces are ________
a) gravitational forces between atoms
b) electromagnetic forces between atoms
c) nuclear forces within an atom
d) combination of gravitational & nuclear forces between atoms
Answer: b
Clarification: In a solid body, the atoms are held together in structures by interatomic forces which are electromagnetic in nature. When forces deform the solid structure, the atoms are displaced from their equilibrium positions. On removal of these external forces the atoms try to regain their original positions because of these intermolecular forces.