1. | tensile, \(F \over 3A\) |
2. | compressive, \(F \over 3A\) |
3. | tensile, \(2F \over 3A\) |
4. | compressive, \(2F \over 3A\) |
A heavy mass is attached to a thin wire and is whirled in a vertical circle. The wire is most likely to break:
1. | when the mass is at the highest point |
2. | when the mass is at the lowest point |
3. | when the wire is horizontal |
4. | at an angle of \(\cos^{-1}(\frac{1}{3})\) from the upward vertical |
The maximum load a wire can withstand without breaking when its length is reduced to half of its original length, will:
1. | be doubled |
2. | be halved |
3. | be four times |
4. | remain the same |
A mild steel wire of length \(\mathrm{2L}\) and cross-sectional area \(A\) is stretched, well within the elastic limit, horizontally between two pillars (figure). A mass \(m\) is suspended from the mid-point of the wire. Strain in the wire is:
1. \( \frac{x^2}{2 L^2} \)
2. \(\frac{x}{\mathrm{~L}} \)
3. \(\frac{x^2}{L}\)
4. \(\frac{x^2}{2L}\)