Heating of ferromagnetic materials to a temperature above Curie temperature makes it
Insulator for heat & electricity transmission
Ferritic
Behave like paramagnetic materials
Superconductor
Correct Answer :
C. Behave like paramagnetic materials
Related Questions
Laser welding is widely employed in the __________ industries.
Electronic
Structural
Process
Heavy
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
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
For dynamic strain measurement, the Wheatstone bridge used is of __________ type.
Voltage sensitive null
Voltage sensitive deflected
Current sensitive deflected
None of these
A reduction in thermal resistance during heat transfer does not occur in the
Convection heat transfer by stirring the fluid and cleaning the heating surface
Conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity
Radiation heat transfer by increasing the temperature and reducing the emissivity
None of these
Enzymes belong to the category of
Proteins
Carbohydrates
Vitamins
Fats
Fine grained steels have
High brittleness
Higher tendency to distort
High ductility
None of these
Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of
Grashoff number
Grashoff number & Reynolds number
Reynolds number
Grashoff number & Prandtl number
Powder metallurgy is used to produce
High precision components with complex cavities and sharp features
Components of large size
Porosity free components
Components of such alloys whose constituents do not form alloys readily
Electrometallurgical methods of metal extraction is normally used for those metals
Whose oxide/ore is not reduced by carbon
Which fall in the category of alkali & alkaline earth metals
Which stands higher in the electrochemical series of the metal
All (A), (B) & (C)
__________ wire is never used for making the heating element.
Nichrome
Kanthal
Invar
None of these
In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be
Conduction
Radiation
Natural convection
Forced convection
Corrosion rate cannot be lowered by reducing the __________ of the corroding medium.
Concentration
Velocity
Temperature
None of these
Large diameter reinforced cement concrete (RCC) pipes are generally joined by __________ joint.
Flanged iron
Collar
Flexible
Expansion
Which of the following is an undesirable property of slag produced during the Pyrometallurgical method of metal extraction from its ore?
High fusibility & fluidity
High thermal conductivity
Low density
High chemical activity
Dryness factor of steam is defined as the ratio of the mass of vapor in the mixture to the mass of the mixture. Dryness factor of steam is measured by a __________ calorimeter.
Bomb
Throttling
Junker's
Boy's
One of the methods of purification of leach liquor is ion exchange, which involves
Exchange between two liquid phases
Exchange between a gaseous phase and a liquid phase
Exchange between a liquid phase and an organic resin phase
Exchange between a solid phase and a gas phase
In case of brasses, with decreasing zinc percentage and increasing copper percentage, its __________ increases.
Percentage elongation
Brinell hardness
Tensile strength
All 'a', 'b' & 'c'
The elastic strain in copper is due to the
Motion of dislocations
Stretching of atomic bonds
Breakage of atomic bonds
None of the above
Which of the following is not the function of a volute casing provided in a centrifugal pump?
To reduce the head loss in discharge
To increase the pump efficiency
To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at constant velocity
To increase the pump discharge rate
For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = - 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be
30,000 J
60,000 J
90,000 J
2,40,000 J
Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs?
Enthalpy
Relative humidity
Wet bulb temperature
Dew point temperature
What is the range of tempering temperature (°C) for most of the materials?
75-100
200-300
350-450
500-600
at 1173E; at equilibrium, what will be the number of moles of CO gas required to reduce one mole of 
at 1173 K?
1.0
1.3
2.3
3.3
If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity
Is trebled
Remains unchanged
Decreases by a factor of 3
Decreases by a factor of 1/3
Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal
Tensile strength
Compressive strength
Young's modulus
Thermal co-efficient of expansion
A jet engine turbine blade is normally manufactured by
Forging
Shell moulding
Investment casting
Pressure die casting
Adhesives
Cant be used in the form of pressure sensitive tapes
Cant join two dissimilar metals
Cure instantaneously after application on a surface
None of these
Pick out the wrong statement.
Lead can creep under its own weight at room temperature
The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
Recrystallisation temperature decreases with decrease in strain in a cold worked metal
With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
__________ joint is mostly used for joining pipes carrying water at low pressure.
Nipple
Socket
Union
Bell and spigot