Young's Modulus Experiment Viva Questions

Viva Questions on Young's Modulus Experiment

1. What is meant by stress?

Ans: Stress is defined as the restoring force that is acting per unit area of a body.

2. What is meant by strain?

Ans: Strain is defined as the ratio of change in dimension to the original dimension.

3. What is the unit of stress?

Ans: Nm-2

4. What is the unit of strain?

Ans: No unit.

5. Define elasticity.

Ans: The property of a body to recover its original pattern when the deforming forces are removed is called elasticity.

6. Who was the first man to investigate the stretching of metals?

Ans: Robert Hooke

7. State Hooke's law.

Ans: Within the elastic limit, the stress grown is directly proportional to the strain created in a body.

8. Which is more elastic either steel wire or rubber wire of same diameters and lengths?

Ans: Steel wire

9. What is meant by Young's Modulus of elasticity?

Ans: The ratio between the normal stress to the longitudinal strain in elastic limit is called as Young's modulus of elasticity.

10. What is the unit of elastic limit?

Ans: Nm-2

11. Distinguish between stress and pressure.

Ans: The restoring force acting per unit area is Stress and the amount of force applied per unit area is Pressure.

12. What is meant by elastic limit?

Ans: The maximum stress for a body can withstand before the permanent deformation of size or shape.

13. What is the modulus of elasticity?

Ans: The relationship (ratio) between stress and strain is called as Modulus of Elasticity (Young's modulus of elasticity).

λ = stress/strain

14. What are the different moduli of elasticity?

Ans: (i) Young's modulus,

(ii) Shear modulus, and

(iii) Bulk modulus.

15. What is the unit of modulus of elasticity?

Ans: Nm-2 or Pa

16. Why do you use a micrometer or vernier instead of a metre scale to measure the increase in length of the wire?

Ans: It is because the vernier can slide freely against the main scale.

17. What is elastic hysteresis?

Ans: Elastic Hysteresis is the difference between the strain energy and stress energy. It is the lagging of strain behind the stress.

18. Aim of Young's Modulus Experiment

Ans: To find out the Young's modulus of the material for a given wire by Searle's apparatus.

19. Apparatus of Young's Modulus Experiment

Ans: The Searl's apparatus, weight hanger, slotted weights, screw gauge, metre rule etc. The Searl's apparatus consists of two long metal wires AB and CD each of length about 2 m suspended side by side from a rigid support. AB is the experimental wire whose Young's modulus is to be determined. CD is the observation wire. The experimental wire AB carries a vernier V and the observation wire CD carries a main scale S. The vernier can slide freely against the main scale. The observation wire is made taut by suspending a load W at the lower end of the main scale.

20. Procedure of Young's Modulus Experiment