A 5 m long aluminium wire (Y=7×1010N/m2) of diameter 3 mm supports a 40 kg mass. In order to have the same elongation in a copper wire (Y=12×1010N/m2) of the same length under the same weight, the diameter of the copper wire should be, in mm:
1. 1.75
2. 1.5
3. 2.5
4. 5.0
A steel wire of 1 m long and cross section area 1 mm2 is hang from rigid end. When mass of 1kg is hung from it then change in length will be: (given Y=2×1011N/m2)
1. 0.5 mm
2. 0.25 mm
3. 0.05 mm
4. 5 mm
An iron rod of length 2m and cross section area of 50 X 10-6 m2 , is stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young's modulus of the iron rod is-
1. 19.6×1010N/m2
2. 19.6×1015N/m2
3. 19.6×1018N/m2
4. 19.6×1020N/m2
In which case, there is a maximum extension in the wire, if the same force is applied on each wire?
1. L = 500 cm, d = 0.05 mm
2. L = 200 cm, d = 0.02 mm
3. L = 300 cm, d = 0.03 mm
4. L = 400 cm, d = 0.01 mm
The extension of a wire by the application of load is 3 mm. The extension in a wire of the same material and length but half the radius by the same load is -
1. 12 mm
2. 0.75 mm
3. 15 mm
4. 6 mm
The isothermal elasticity of a gas is equal to
1. Density
2. Volume
3. Pressure
4. Specific heat
The adiabatic elasticity of a gas is equal to
1. γ × density
2. γ × volume
3. γ × pressure
4. γ × specific heat
The specific heat at constant pressure and at constant volume for an ideal gas are Cp and Cv and its adiabatic and isothermal elasticities are E∅ andEθ respectively. The ratio of E∅ to Eθ is
1. Cv/Cp
2. Cp/Cv
3. CpCv
4. 1/CpCv
If the volume of the given mass of a gas is increased four times and the temperature is raised from 27°C to 127°C. The isothermal elasticity will become
1. 4 times
2. 1/4 times
3. 3 times
4. 1/3 times
The compressibility of water is 4×10-5 per unit atmospheric pressure. The decrease in volume of 100 cubic centimeter of water under a pressure of 100 atmosphere will be -
1. 0.4 cc
2. 4×10-5cc
3. 0.025 cc
4. 0.004 cc