Elasticity

Q. The diagram shows a force-extension graph for a rubber band. Consider the following statements




I.It will be easier to compress this rubber than expand it
II.Rubber does not return to its original length after it is stretched
III.The rubber band will get heated if it is stretched and released
Which of these three statements can be deduced from the graph?

1. III only
2. II and III
3. I and III
4. I only

Q. Ultimate tensile strength of a metallic wire depends on its

1. Length
2. Area of cross-section
3. Material
4. None of these

Q. A material which stretches more is more elastic.

1. False
2. True

Q. The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity $\eta$ is

1. $y=\frac{9\eta k}{\eta +3K}$
2. $y=\frac{9YK}{Y+3K}$
3. $y=\frac{9\eta k}{3+K}$
4. $y=\frac{3\eta k}{9\eta +K}$

Q. A pan with set of weights is attached with a light spring. When disturbed, the mass-spring system oscillates with a time period of 0.6s. When some additional weights are added then time period is 0.7s. The extension caused by the additional weights is approximately

1. 1.38 cm
2. 3.5 cm
3. 1.75 cm
4. 2.45 cm

Q. Materials which do not have a certain organized arrangement of atoms and molecules are also known as

1. Crystalline solids
2. Amorphous solids
3. Ionic solids
4. Metallic solids

Q. If in a wire of Young's modulus $Y$, longitudinal strain $X$ is produced, then the elastic potential energy stored in its unit volume will be

1. $0.5Y{X}^2$
2. $0.5Y^{2}X$
3. $2Y{X}^2$
4. $Y{X}^2$

Q. A wire suspended vertically from one of its ends is stretched by attaching a weight of $200\text{N}$ to its lower end. If the weight stretches the wire by $1\text{mm}$, then elastic energy stored in the wire is

1. $0.1\text{J}$
2. $0.2\text{J}$
3. $10\text{J}$
4. $20\text{J}$

Q. The property of a material to restore its natural shape or to oppose deformation is called

1. Rigidity
2. Elasticity
3. Plasticity
4. Deformability

Q. All solids are perfectly elastic.

1. False
2. True

Q. When a uniform metallic wire is stretched the lateral strain produced in it is $\beta$. If $\nu$ and $Y$ are the Poisson's ratio and Young's modulus for the wire, then elastic potential energy density of wire is

1. $\frac{Y{\beta }^2}{2}$
2. $\frac{Y{\beta }^2}{2{\nu }^2}$
3. $\frac{Y\nu {\beta }^2}{2}$
4. $\frac{Y{\nu }^2}{2\beta }$

Q. If in a wire of Young's modulus $Y$, longitudinal strain $X$ is produced, then the elastic potential energy stored in its unit volume will be

1. $0.5Y{X}^2$
2. $0.5Y^{2}X$
3. $2Y{X}^2$
4. $Y{X}^2$