A wire can sustain a weight of 10 kg before breaking. If the wire is cut into two equal parts, then each part can sustain a weight of:
1. | 2.5 kg | 2. | 5 kg |
3. | 10 kg | 4. | 15 kg |
A 1000 kg lift is tied with metallic wires of maximum safe stress of 1.4 108 N m-2. If the maximum acceleration of the lift is 1.2 m s-2, then the minimum diameter of the wire is:
1. 1 m
2. 0.1 m
3. 0.01 m
4. 0.001 m
Overall changes in volume and radius of a uniform cylindrical steel wire are 0.2% and 0.002% respectively when subjected to some suitable force. Longitudinal tensile stress acting on the wire is: ( )
1.
2.
3.
4. 3.9
Choose the correct statement.
1. | Breaking stress does not depend on the area of cross-section. |
2. | \(\mathrm{B}_{\text {solid }}>\mathrm{B}_{\text {gas }}>\mathrm{B}_{\text {liquid }}\)where B is the bulk modulus. |
3. | Breaking load does not depend on the area of cross-section. |
4. | Young's modulus always decreases on decreasing the temperature. |
A steel ring of radius \(\mathrm{r}\) and cross-section area \(\mathrm{A}\) is fitted onto a wooden disc of radius \(\mathrm{R}(\mathrm{R}>\mathrm{r}).\) If Young's modulus is \(\mathrm{E},\) then the force with which the steel ring is expanded is:
1. | \(\mathrm{AE} \frac{\mathrm{R}}{\mathrm{r}} \) | 2. | \(A E \frac{R-r}{r} \) |
3. | \(\frac{E}{A} \frac{R-r}{A} \) | 4. | \(\frac{\mathrm{Er}}{\mathrm{AR}}\) |
A light rod of length 2m is suspended from the ceiling horizontally by means of two vertical wires of equal length. A weight W is hung from the light rod as shown in the figure. The rod is hung by means of a steel wire of cross-sectional area and brass wire of cross-sectional area . To have equal stress in both wires, =?
1. | 1/3 | 2. | 1/4 |
3. | 4/3 | 4. | 1/2 |
The stress versus strain graphs for wires of two materials A and B are as shown in the figure. If are the Young's moduli of the materials, then:
1. | YB = 2YA | 2. | YA = YB |
3. | YB = 3YA | 4. | YA = 3YB |
Copper of fixed volume \(V\) is drawn into a wire of length \(l.\) When this wire is subjected to a constant force \(F,\) the extension produced in the wire is \(\Delta l.\) Which of the following graphs is a straight line?
1. \(\Delta l ~\text{vs}~\frac{1}{l}\)
2. \(\Delta l ~\text{vs}~l^2\)
3. \(\Delta l ~\text{vs}~\frac{1}{l^2}\)
4. \(\Delta l ~\text{vs}~l\)
Two wires are made of the same material and have the same volume. The first wire has a cross-sectional area \(A\) and the second wire has a cross-sectional area \(3A\). If the length of the first wire is increased by \(\Delta l\) on applying a force \(F\), how much force is needed to stretch the second wire by the same amount?
1. | \(9F\) | 2. | \(6F\) |
3. | \(4F\) | 4. | \(F\) |
A vessel of \(1\times 10^{-3}\) m3 volume contains oil. When a pressure of \(1.2 \times10^5\) N/m2 is applied on it, then volume decreases by \(0.3 \times 10^{-6}\) m3. The bulk modulus of oil is:
1. | \(1 \times 10^6 \mathrm{~N} / \mathrm{m}^2 \) | 2. | \(2 \times 10^7 \mathrm{~N} / \mathrm{m}^2 \) |
3. | \(4 \times 10^8 \mathrm{~N} / \mathrm{m}^2 \) | 4. | \(6 \times 10^{10} \mathrm{~N} / \mathrm{m}^2\) |