Hooke's law is applicable for:

1.	elastic materials only	2.	plastic materials only
3.	elastomers only	4.	all of these

When a load of 10 kg is suspended on a metallic wire, its length increase by 2mm. The force constant of the wire is

1. $3\times {10}^4 \mathrm{N}/\mathrm{m}$

2. $2.5\times {10}^3 \mathrm{N}/\mathrm{m}$

3. $5\times {10}^4 \mathrm{N}/\mathrm{m}$

4. $7.5\times {10}^3 \mathrm{N}/\mathrm{m}$

The figure shows the graph between stress and strain for a uniform wire at two different temperatures. Then:

1. \(T_1>T_2\)
2. \(T_2>T_1\)
3. \(T_1=T_2\)
4. None of these

If two different types of rubber are found to have stress-strain curves as shown, then:
                   

The stress-strain graphs for two materials \(A\) and \(B\) are shown in the figure. The graphs are drawn to the same scale. Select the correct statement:

1. material \(A\) has a greater Young's Modulus.
2. material \(A\) is ductile. 
3. material \(B\) is brittle.
4. all of these.

The load versus elongation graph for four wires of same length and the same material is shown in figure. The thinnest wire is represented by line:

1. OC

2. OD

3. OA

4. OB

In the given figure, if the dimensions of the two wires are the same but materials are different, then Young's modulus is

1. More for A than B

2. More for B than A

3. Equal for A and B

4. None of these

The length of wire, when M₁ is hung from it, is l₁ and is l₂ with both M₁ and M₂ hanging. The natural length of wire is

1. $\frac{{\mathrm{M}}_1}{{\mathrm{M}}_2}({\mathrm{l}}_1-{\mathrm{l}}_2)+{\mathrm{l}}_1$

2. $\frac{{\mathrm{M}}_2{\mathrm{l}}_1-{\mathrm{M}}_1{\mathrm{l}}_2}{{\mathrm{M}}_1+{\mathrm{M}}_2}$

3. $\frac{{\mathrm{l}}_1+{\mathrm{l}}_2}{2}$

4. $\sqrt{{\mathrm{l}}_1{\mathrm{l}}_2}$

The substances having very short plastic region are

1. Ductile

2. Brittle

3. Malleable

4. All of these

Due to the addition of impurities, the modulus of elasticity:

1. Decreases

2. Increases

3. Remains constant

4. May increase or decrease