The breaking stress of a wire depends upon:
1. | material of the wire. |
2. | length of the wire. |
3. | radius of the wire. |
4. | shape of the cross-section. |
The breaking stress of a wire going over a smooth pulley in the following question is 2×109 N/m2. What would be the minimum radius of the wire used if it is not to break?
1. | 0.46×10−6 m | 2. | 0.46×10−4 m |
3. | 0.46×108 m | 4. | 0.46×10−11 m |
A light rod of length 2 m 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 A1=0.1 cm2 and brass wire of cross-sectional area A2=0.2 cm2. To have equal stress in both wires, T1T2?
1. | 13 | 2. | 14 |
3. | 43 | 4. | 12 |
To break a wire, a force of 106 N/m2 is required. If the density of the material is 3×103 kg/m3, then the length of the wire which will break by its own weight will be:
1. 34 m
2. 30 m
3. 300 m
4. 3 m
A uniform wire of length 3 m and mass 10 kg is suspended vertically from one end and loaded at another end by a block of mass 10 kg. The radius of the cross-section of the wire is 0.1 m. The stress in the middle of the wire is: (Take g=10 ms-2)
1. | 1.4×104 N/m2 | 2. | 4.8×103 N/m2 |
3. | 96×104 N/m2 | 4. | 3.5×103 N/m2 |
lf ρ is the density of the material of a wire and σ is the breaking stress, the greatest length of the wire that can hang freely without breaking is:
1. 2ρg
2. ρσg
3. ρg2σ
4. σρg
One end of a uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight W1 is suspended from its lower end. If A is the area of the cross-section of the wire, the stress in the wire at a height 3L4 from its lower end is:
1. W+W1A
2. 4W+W13A
3. 3W+W14A
4. 34W+W1A
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 |
The length of an elastic string is a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when the longitudinal tension is 9 N will be:
1. | a−b | 2. | 5b−4a |
3. | 2b−14a | 4. | 4a−3b |