| 1. | \(B_1\) | 2. | \(2B_1\) |
| 3. | \( \dfrac {B_1}{2}\) | 4. | \(\dfrac {B_1}{\sqrt 2}\) |
| 1. | 2. | ||
| 3. | 4. |

| 1. | no stress | 2. | compressive stress |
| 3. | tensile stress | 4. | shear stress |
1. tensile| 1. | \(\dfrac{3 M g l}{A Y}\) | 2. | \(\dfrac{2 M g l}{A Y}\) |
| 3. | \(\dfrac{3 M g l}{2 A Y}\) | 4. | \(\dfrac{M g l}{A Y}\) |
| 1. | tensile, \(\dfrac{F}{3A}\) | 2. | compressive, \(\dfrac{F}{3A}\) |
| 3. | tensile, \(\dfrac{2F}{3A}\) | 4. | compressive, \(\dfrac{2F}{3A}\) |
Two wires of identical dimensions but of different materials having Young's moduli \(Y_1, Y_2\) are joined end to end. When the first wire is under a tension \(T,\) it elongates by \(x_1\) while the second wire elongates by \(x_2\) under the same tension \(T.\) The elongation of the composite wire when it is under tension \(T\) is:
| 1. | \(x_1+x_2\) | 2. | \(\dfrac{Y_1x_1+Y_2x_2}{Y_1+Y_2}\) |
| 3. | \(\dfrac{x_1+x_2}{2}\) | 4. | \(\dfrac{Y_1x_2+Y_2x_1}{Y_1+Y_2}\) |