The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is
More
Equal
Less
Double
Correct Answer :
A. More
Related Questions
Between 230 and 370°C, blue brittleness is caused in mild steel because of the
Immobility of dislocation
Strain-ageing
Increase in Young's modulus
Strain hardening
Identify the false statement
Martensitic steels are less susceptible to pitting corrosion than austenitic steels
Pitting corrosion is usually very localised
Hydrogen embrittlement is facilitated by tensile stress
Stress corrosion cracking is facilitated by tensile stress
Fog is an example of colloidal system of
Solid dispersed in gas
Solid dispersed in liquid
Liquid dispersed in gas
Gas dispersed in liquid
Wrought iron is not
Ductile & resistant to corrosion/rusting
Weldable easily
Having uniform strength in all directions
Having maximum tensile strength along the lines of slag distribution
Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity.
300
800
1400
2000
Which of the following is not a characteristic observed in material failure by fatigue fracture?
Plastic deformation of material does not occur
Initiation of crack from below the surface does not occur
Initiation of crack occurs on the surface of the machine part
Presence of both rough & smooth zone with conchoidal markings in smooth zone of the surface
The expected efficiency of a single riveted lap joint is of the order of 50%. If the thickness of the plate is increased four times, then the rivet diameter will have to be increased __________ times.
Two
Four
Six
Eight
What is the pH of distilled water?
0
1
7
14
The product of a commercial direct reduction process is
Liquid iron
Solid iron
Sponge iron
Iron saturated with carbon
Annealing of white cast iron produces __________ iron.
Grey
Nodular
Malleable
Spheroidal
With increase in temperature, the surface tension of water
Increases
Decreases
Remain constant
Increases linearly
Larger length & diameter water pipes are made by
Electrical resistance welding
Die casting
Semi-centrifugal casting
Continuous casting
Rain drops falling through atmospheric air attain limited terminal velocity, because of
Upward thrust due to air
Viscous force exerted by air
Surface tension effects of water
Force of gravity
Fine grained steels have
High brittleness
Higher tendency to distort
High ductility
None of these
The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air.
Ambient
Dry bulb
Dew point
Wet bulb
Wrought iron is never shaped by
Casting
Cold working
Forging
Welding
In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be
ΔQ = 0, ΔS=0
ΔQ = 0, ΔS = +ve
ΔQ = 0, ΔS = -ve
ΔQ = +ve, ΔS= +ve
Diameter of the rivet to be provided on a 20 mm. thick boiler plate will be __________ mm.
10
20
30
40
The two elements required to form substitutional solid solution should not have
Same crystalline structure
Same valency
Widely differing electronegativity
Same atomic sizes
Energy to be supplied to the radioactive nucleus for the emission of a neutron is __________ MeV.
0.8
7.8
200
10000
The amount of different substances produced, when the same quantity of electricity is passed through different solutions are proportional to their
Equivalent weight
(Equivalent weight)2
Molecular weight
(Molecular weight)2
Speed of a submarine in deep sea & that of an aeroplane is measured by a/an
Pitot tube
Hot wire anemometer
Rotameter
Stroboscope
Which of the following terminology is used for the temperature at which new grains are formed in a metal?
Eutectic temperature
Lower critical temperature
Recrystallisation temperature
Upper critical temperature
Removal of non-condensable from steam or other vapour is termed as the __________ process.
Condensation
Deaeration
Scavenging
Exhaust
Tumbling is the process of improving the __________ of the materials/parts.
Surface finish
Fatigue limit
Creep limit
Surface cleanliness
Metal shots used in shot blasting are made of
Stellite
Steel
Bronze
Lead
The surface tension of a liquid, at critical temperature is
Indeterminate
Zero
Infinity
Same as that at any other temperature
Austempering of steel requires it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to
Sorbite
Bainite
Martensite
Troostite
Alloying elements present in Haynes stellite, which has superior performance than high speed steel, are:
Nickel, cobalt & chromium
Tungsten, chromium & cobalt
Manganese, chromium & cobalt
Tungsten, molybdenum & nickel
A polymer is termed as an 'elastomer', if its percentage elongation is more than 100%. An elastomer is termed as 'rubber' if its percentage elongation is more than __________ percent.
150
200
300
400