Which of the following affects the elasticity of a substance

1. Hammering and annealing

2. Change in temperature

3. Impurity in substance

4. All of these

Which one of the following quantities does not have the unit of force per unit area?

1. Stress                                      

2. Strain

3. Young's modulus of elasticity

4. Pressure

In steel, the Young's modulus and the strain at the breaking point are $2\times {10}^{11}N{m}^{-2}$ and 0.15 respectively. The stress at the breaking point for steel is therefore -

1. $1.33\times {10}^{11}N{m}^{-2}$           

2. $1.33\times {10}^{12}N{m}^{-2}$

3. $7.5\times {10}^{-13}N{m}^{-2}$           

4. $3\times {10}^{10}N{m}^{-2}$

The quality of the material which opposes the change in shape, volume or length is called

1.   Intermolecular repulsion

2.   Intermolecular behaviour

3.   Viscosity

4.   Elasticity

Which one of the following substances possesses the highest elasticity:

1. Rubber                             

2. Glass

3. Steel                               

4. Copper

A wire of length L and radius r is  rigidly fixed at one end. On stretching the other end of the wire with a force F, the increase in its length is l. If another wire of same material but of length 2L and radius 2r is stretched with a force of 2F, the increase in its length will be

1. l                                       
2. 2l
3. $\frac{l}{2}$                                   
4. $\frac{l}{4}$ 

The possible value of Poisson's ratio is

1. 1                                       

2. 0.9

3. 0.8                                     

4. 0.4

A copper wire and a steel wire of the same diameter and length are connected end to end and a force is applied, which stretches their combined length by 1 cm. The two wires will have

1. Different stresses and strains

2. The same stress and strain

3. The same strain but different stresses

4. The same stress but different strains