Alloy powder manufactured by the following process have spherical shapes.
Electrochemical deposition
Gaseous reduction
Atomisation
Mechanical attrition
Correct Answer :
C. Atomisation
Related Questions
Wrought iron does not have
Uniform strength in all directions
Ability to hold protective coating
High ductility & corrosion resistance
Easily weldable characteristics
Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity.
300
800
1400
2000
The most detrimental impurity in high pressure boiler feed water is
Suspended salt
Dissolved salt
Silica
Turbidity
With increase in compression ratio, the volumetric efficiency of air compressor
Increases
Decreases
Remain same
May increase or decrease (depends on the suction pressure)
Damage to metal surface by mechanical action is called
Pitting
Corrosion
Erosion
None of these
Particle nature of cathode rays is proved due to the fact that they
Travel in a straight line
Get deflected by magnetic electric field
Produce fluorescence
Heat the exposed material
Out of the following, the joint produced by __________ has the lowest strength.
Soldering
Welding
Brazing
Riveting
Solute atoms which cause yield point phenomenon in mild steel are/is
Aluminium
Boron
Carbon
Nitrogen
Half life of a radioactive isotope corresponds to the time required for half of the __________ to decay.
Atoms
Neutrons
Nucleons
Electrons
A material is capable of resisting softening at high temperature, because of its property termed as
Hot temper
Hot hardness
Fatigue
Creep
Heating the Hypo-eutectoid steels to 30°C above the upper critical temperature line, soaking at that temperature and then cooling slowly to the room temperature to form a pearlite & ferrite structure is called
Tempering
Hardening
Annealing
Normalising
Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of
90% tungsten carbide and 10% cobalt
70% aluminium oxide & 30% silica
30% nickel, 15% chromium & 55% tungsten
65% tungsten & 35% zirconium
Temperature profile along the length of a gasgas counter flow heat exchanger is correctly represented by
Velocity of a gas in sound is not proportional to (where, T = Absolute temperature of the gas. P = Absolute pressure of the gas. y = Ratio of specific heats (Cp/Cv) ρ = specific weight of the gas)
√T
1/√P
√y
1/√ρ
Temper brittleness of a material can be fairly detected by the __________ test.
Fatigue
Notched bar impact
Tensile
Hardness
Diameter of the rivet to be provided on a 20 mm. thick boiler plate will be __________ mm.
10
20
30
40
__________ test determines the yield strength, Young's modulus of elasticity, percentage reduction in area & percentage elongation of a material.
Tensile
Fatigue
Impact
None of these
__________ remains constant during the adiabatic cooling of moist air.
Wet bulb temperature
Dry bulb temperature
Relative humidity
Specific humidity
Which of the following alloying elements is present in maximum percentage in high speed steel?
Molybdenum
Chromium
Tungsten
Vanadium
Lead pencil contains
Graphite
Lead sulphide
Lead
Both (B) & (C)
Force between the molecules of the same substance is called __________ force.
Adhesive
Cohesive
Molecular
Vander Walls
A common disinfectant used in village wells for disinfection of water is
Free chlorine
Bromine
Iodine
Potassium permanganate
Dry saturated steam can be converted into superheated steam by
Increasing its cross-sectional area of flow
Passing it through a pressure reducing valve
Forcing it downwards through a vertical tube
None of these
__________ is not used as the control rod material in a nuclear reactor.
Cobalt
Hafnium
Cadmium
Boron
Photographic plates are coated with
Silver nitrate
Silver halide
Calcium silicate
Metallic silver
The most suitable material of construction for a sewer to carry sewage under high pressure is
Asbestos cement
Steel
Cement concrete
Stoneware
The main charge in blast furnace is usually
Iron ore & coke
Iron ore, coke & air
Limestone, coke & iron ore
Limestone, sand & iron ore
Water hammer is caused in steam carrying pipelines, because of
Partial condensation of steam
Vibration of the pipeline
High degree of superheat of steam
Its exposure to torrential rain
Tip of the match stick contains a mixture of
K + S
K + S + K2Cr2O7
S + K2Cr2O7 + White P
None of these
Pick out the wrong statement about nucleate boiling.
Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface
Surface temperature is greater than the saturation temperature of the liquid
Heat transfer from the surface of the liquid is less than that in film boiling
The temperature is less than that of film boiling