Which of the following relationships is correct for relating the three elastic constants of an isotropic elastic material (where, E = Young's modulus, G = Modulus of rigidity or shear modulus v = Poisson's ratio)?
A. E = 2G (1 + v)
B. E = G (1 + v)
C. E = 2 G ( 1 + v )
D. E = 2G (1 + 2v)
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Dephosphorisation of molten pig iron is favoured by
A. Oxidising and basic slag
B. Reducing and basic slag
C. High activity co-efficient of phosphorous in metal
D. Oxidising and neutral slag
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Commonly used flux for brazing is
A. Zinc chloride
B. Borax
C. Ammonium chloride
D. Rosin
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For a small scale toy factory, the fixed cost per month is Rs. 5000/-. The variable cost per toy is Rs. 20 and sales price is Rs. 30 per toy. The break even production per month will be __________ toys.
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Air-petrol ratio in an automotive petrol engine is around
A. 14 : 1
B. 22 : 1
C. 25 : 1
D. 4 : 1
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A balanced draught boiler furnace employs __________ draught fan.
A. Induced
B. Forced
C. Both A & B
D. Neither A nor B
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The normal stress is the same in all directions at a point in a fluid, only when the fluid
A. Is at rest & has zero viscosity
B. Is frictionless
C. Fluid layer has no motion relative to an adjacent layer of fluid
D. Is incompressible & frictionless
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Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50 wt% B is
A. R ln 2
B. -R ln 2
C. 3R ln 2
D. -3R ln 2
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__________ of test specimens is not involved in any hardness testing method.
A. Fracture
B. Indentation
C. Wear
D. Scratch
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The materials which fracture even at small strains are termed as brittle, while those materials which exhibit an appreciable deformation before failure are termed as
A. Rigid
B. Tough
C. Ductile
D. Plastic
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Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about __________ percent.
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Joule-Thomson co-efficient is the ratio of
A. Pressure change to temperature change occuring during adiabatic compression of a gas
B. Pressure change to temperature change occuring during adiabatic throttling of a gas
C. Temperature change to pressure change occuring during adiabatic compression of a gas
D. Temperature change to pressure change occuring during adiabatic throttling of a gas
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Percentage of argon (by volume) in dry atmospheric air is about
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Iron has got __________ isotopes.
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Addition of __________ to steel does not help in improving its machinability.
A. Sulphur
B. Silicon
C. Lead
D. Phosphorous
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Density in the solid state is slightly less than that in its liquid state, in case of
A. Carbon dioxide
B. Water
C. Mercury
D. None of these
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On an average __________ fast neutrons are produced by nuclear fission of each atom of uranium-235.
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A dummy activity is used in PERT network to describe the
A. Precedence relationship
B. Resource idleness
C. Resource restriction
D. Necessary time delay
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__________ method of depreciation calculation ensures that the interest is charged on the cost of machine asset every year on the book value, but the rate of depreciation remains constant every year.
A. Annuity charging
B. Atraight line
C. Ainking fund
D. None of these
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Eutectoid composition of carbon steel at room temperature is
A. Cementite
B. Pearlite
C. Martensite
D. Ferrite
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