Joining of thin foils is preferred to be done by
Gamma rays
X-rays
Microwaves
Gas welding
Correct Answer :
C. Microwaves
Related Questions
If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor.
Critical
Breeder
Fertile
Heterogeneous
Uniform ramming of sand in green sand moulding process leads to
Reduced chance of gas porosity
Greater dimensional stability of the casting
Uniform flow of molten metal into the mould cavity
Less sand expansion type of casting defect
Dielectric
Is an electrical insulating material
Of low resistivity is preferred
Should have high thermal conductivity
Need not defy the corrosive action of chemicals
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
With increasing carbon percent in steel beyond 0.8%, its ultimate tensile strength (UTS) and __________ is not affected.
Impact strength
Percent elongation
Hardness
Both 'b' & 'c'
For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot?
Temperature - entropy
Temperature - pressure
Enthalpy - entropy
Enthalpy-pressure
Pick out the wrong statement about coating/electroplating of metals.
Phosphate coating is used as an excellent base for paints & enamels
Phosphate coating is less corrosion resistant than chromate coating
The base metal to be electroplated is normally made the cathode of the electrolytic cell and coating metal is made the anode
Calorising is the process of coating steel with chromium
Electrometallurgy is not involved in the extraction of __________ from its ore.
Aluminium
Tin
Lead
Both (B) & (C)
An approximately __________ process exemplifies the flow of a gas through a very long pipe of uniform cross-section.
Adiabatic
Isothermal
Isentropic
Isochoric
__________ are normally subjected to sub-zero treatment.
Highly stressed parts
Gauges or precision parts
Cold rolled sheets
Non machinable materials
The product of a commercial direct reduction process is
Liquid iron
Solid iron
Sponge iron
Iron saturated with carbon
An alloy of Fe - 0.4 % C is
Cast iron
Hypo-eutectoid steel
Hyper-eutectoid steel
Eutectoid steel
Nusselt number/Biot number varies
Inversely with thermal conductivity
Directly with heat transfer co-efficient
Directly with thermal conductivity
Inversely with the dimension of the solid
Most important property of steels for use in automobile bodies is the
Formability
Yield strength
Toughness
Resilience
Maximum permissible sulphur content in steel is __________ percent.
0.015
0.055
0.505
0.805
Pick out the wrong conversion of absolute & kinematic viscosities.
1 stoke = 1 cm2/sec
1 N.sec/m2 = 10 paise
1 stoke = 1 m2/sec
1 m2/sec = 104 stokes
Increasing the carbon content of steel
Reduces the upper shelf energy
Increasing the ductility transition temperature
Decreases brittleness
Decreases hardness
Spark plug is provided in a/an
Engine having carburettor
Diesel engine
Compression ignition engine
Both (B) & (C)
Carnot cycle is also termed as the constant __________ cycle in thermodynamics.
Entropy
Pressure
Volume
Heat
__________ of austenite decreases the hardenability in steel.
Fine grains
Coarse grains
Homogeneity
Dissolved elements (except cobalt)
The substance used as a smoke screen in warfare is
C2H2
SiCl4
P2O5
PCl5
__________ wire is never used for making the heating element.
Nichrome
Kanthal
Invar
None of these
While the oxy-acetylene flame produces a temperature of 3200°C, the temperature produced by oxy-hydrogen flame is about __________ °C.
1800
2000
2400
3000
Which of the following is an example of stress corrosion?
Season cracking of brass
Caustic embrittlement of steel
Both (A) & (B)
Neither (A) nor (B)
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
Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
Retained austenite
Martensite formation
Relatively high sulphur content in the base metal
Sufficient hydrogen present in the welding arc
Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part?
Anodising
Tempering
Carburising
Annealing
Milk is fat dispersed in water. It is an example of
Suspension
Emulsion
Gel
Solution
In extrusion of metals, which of the following statement is true?
Speed of the extruded material is same as that of ram speed
Redundant work is a function of the die angle
Relative motion between the billet surface and the container wall is always present
Hollow ram is used for indirect extrusion
Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is
R ln 2
-R ln 2
3 R ln 2
-3R ln 2