Mechanical Properties of Solids · Question 8

The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weights added to the steel and brass wires must be in the ratio of

1. 4 : 1
2. 1 : 1
3. 1 : 2
4. 2 : 1

The approximate depth of an ocean is 2700 m. The compressibility of water is 45.4 10-11 Pa-1 and density of water is 103 kg/m3. What fractional compression of water will be obtained at the bottom of the ocean?

1. 1.2 10-2
2. 1.4 10-2
3. 0.8 10-2
4. 1.0 10-2

Copper of fixed volume V is drawn into wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is l. Which of the following graphs is a straight line ?

1. l versus 1l
2. l versus l2
3. l versus 1l2
4. l versus l

The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?

1. length = 200 cm, diameter = 2 mm
2. length = 300 cm, diameter = 3 mm
3. length = 50 cm, diameter = 0.5 mm
4. length = 100 cm, diameter = 1 mm

If the ratio of diameters, lengths and Young's modulus of steel and copper wires shown in the figure are p, q and s respectively, then the corresponding ratio of increase in their lengths would be [figure]

1. ( 5q7sp2 )
2. ( 7q5sp2 )
3. ( 2q5sp )
4. ( 7q5sp )