In the given figure, if the dimensions of the wires are the same and materials are different, Young's modulus is more for :
B
A
Both (a) and (b)
None of these
A steel wire of uniform cross-section of 2 mm2 is heated upto 50oC and clamped rigidly at two ends. If the temperature of wire falls to 30oC then change in tension in the wire will be :
(Given : Coefficient of linear expansion of steel is 1.1 x 10-5°C and Young's modulus of elasticity of steel is 2 x 1011N/m2)
22 N
44 N
88 N
132 N
The bulk modulus of rubber is 9 x 108 N/m2. To what depth below the surface of sea should the rubber ball taken as to decrease its volume by 0.1%?
1 m
10 m
100 m
1 km
Two rods of different materials having coefficients of linear expansion α1 and α2 , Young's modulii Y1 and Y2 respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If α1 : α2 =2 : 3, the thermal stresses developed in the two rods are equal provided Y1 : Y2 is equal to :
2 : 3
1 : 1
3 : 2
4 : 9
One end of a uniform wire of length L and weight W is attached rigidly to a point in roof and a weight W1 is suspended from its lower end. If S is the area of corss-section of the wire, the stress in the wire at a height of 3L/4 from its lower end is :
The Poisson's ratio for a material is 0.1. If the longitudinal strain of a rod of this material is 1 x 10-3, then the percentage change in the volume of rod will be :
8%
0.8%
0.08%
0.008%
The Young's modulus of a wire is Y. If the energy per unit volume is E, then the strain will be :
EY
E/Y
An aluminium rod of Young's modulus 7.0 x 109 N/m2 has a breaking strain of 0.2%. The minimum cross-sectional area of the rod in m2 in order to support a load of 104 newton is :
1.0 x 10-2
1.0 x 10-3
1.4 x 10-2
7.1 x 10-4
A thick rope of density 'ρ' and length 'L' is hung from a rigid support. The Young's modulus of the material of rope is 'Y'. The increase in length of the rope due to its own weight is :
1/4 ρgL2/Y
1/2 ρgL2/Y
ρ gL2/Y
ρ gL/Y
A metal block is experencing an atmospheric pressure of 105 N/m2. When the same block is placed in a vaccum chamber, the fractional change in its volume : (the bulk modulus of metal is 1.25 x 1011 N/m2)
8 x 10-7
1 x 10-7
4 x 10-7
2 x 10-7
