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 cross-section of the wire , the stress in the wire at a height 3L/4 from its lower end is:
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The bulk modulus of water is . The increase in pressure required to decrease the volume of water sample by \(0.1\)% is:
1. \(4\times 10^{6}\) N/m2
2. \(2\times 10^{6}\) N/m2
3. \(2\times 10^{8}\) N/m2
4. \(8\times 10^{6}\) N/m2
To break a wire, a force of is required. If the density of the material is , 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
The length of elastic string, obeying Hooke's law is metres when the tension is 4N, and metres when the tension is 5N. The length in metres when the tension is 0 N will be-
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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 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 |
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 'Δl'. Which of the following graph is a straight line?
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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:
( )
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4. 3.9
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
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 uniform cylinder rod of length L, cross-sectional area A and Young's modulus Y is acted upon by the forces, as shown in the figure. The elongation of the rod is:
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