To produce the jog from the intersection of two dislocations, the necessary condition is
A. burger vector of the dislocation should be parallel to each other
B. burger vector of the dislocation should be perpendicular to each other
C. burger vector of the dislocation should be directionally opposite to each other
D. burger vector of the dislocation should be at 45 degrees to each other
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A thermally thin body is the one for which
A. Biot number is less than 0.1
B. Galileo number is less than 0.1
C. Fourier number is less than 0.1
D. Fourier number is greater than 0.1
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Explanation of free energy can be done
A. without temperature
B. with respect to temperature
C. with respect to pressure
D. None of these
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An aluminium alloy rod of diameter 15 mm and length 120 mm is subjected to a tensile load of 35,000 N along its axis. The Young's modulus and Poisson's ratio for aluminium are 70 GPa and 0.33 respectively.
A. 0.11
B. 0.014
C. 0.018
D. 0.021
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A box contains 5 white balls and 3 red balls. Two balls are withdrawn from the box randomly, one after another (without replacement). The probability that the two balls withdrawn are of different colour is
A. 64 15
B. 64 25
C. 56 25
D. 56 30
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Brazing is done at
A. 100 - 450°C
B. 850 - 1050°C
C. 450 - 800°C
D. 1000 - 1200°C
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The density and corresponding crystallinity of two poly-propylene material are given below.
Density.kg.m-3
Crystallinity,%
904
62.8
895
54.4
The density of totally amorphous polypropylene (in kg.m
-3 ) is:
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Greater the amount of deformation
A. Lower is the recrystallization temperature
B. higher is the recrystallization temperature
C. both A and B
D. none of these
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An ability of atoms molecules and ions to diffuse inside the material under the influence of concentration gradient.
A. Diffusivity
B. Planck's law
C. Kirchhoff's law
D. Charl's law
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Most of the thermosetting polymers are
A. amorphous
B. semi-crystalline
C. crystalline
D. transcrystalline
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Which is the correct statement
A. Monomer units form together a co-polymer
B. Monomer units form together a polymerization
C. Monomer units form together a graft polymer
D. Monomer units form together a polymer
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The heat treatment process in which heating of steel is done to a temperature just below the lower critical temperature, holding for prolonged period, followed by slow cooling is called
A. Spheroidise annealing
B. Process annealing
C. Recrystallization annealing
D. Full annealing
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In Laminar flow, the friction factor
A. increases with Reynolds number
B. decreases with Reyonds number
C. depends only upon the velocity of the fluid and increases with the velocity of the fluid
D. depends only upon the density of the fluid and increases with the density of the fluid
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Burger's vector is an/a . . . . . . . . for a crystal
A. Invariant
B. variant
C. univariant
D. trivariant
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The rate of energy radiated per unit area of surface per unit wavelength
A. Monochromatic emissive power
B. diachromatic emissive power
C. polychromatic emissive power
D. None of these
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Which among the following polymers have lowest solubility?
A. Polyethylene
B. polystyrene
C. nylon 6
D. epoxy resin
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in gas welding maximum thickness of material which can be welded with a 30 mm diameter welding rod is
A. 3 mm
B. 6 mm
C. 15 mm
D. 300 mm
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Which of the following oxide addition results in polymerisation (e.g., network formation) in a silicate slag?
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Transmissivity is defined as
A. Fraction of total energy transmitted by the body
B. Fraction of total energy reflected by the body
C. Fraction of total energy absorbed by the body
D. Fraction of total energy absorbed and radiated by the body
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Which property decreases on strain hardening
A. Elastic modulus
B. Percentage elongation
C. Yield strength
D. Hardness
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