The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system
Is as light as possible
Has very high C.O.P.
Employs minimum quantity of refrigerant
Consumer minimum horse power
Correct Answer :
A. Is as light as possible
Related Questions
The softness or hardness of a grinding wheel depends upon the type & amount of bonding material used. For general purpose cutter grinding __________ grinding wheel is normally used.
Hard
Soft
Silicon carbide
Aluminium oxide
Pick out the wrong statement.
Cold cracking of a weld is due to the presence of hydrogen gas in the weld
True stress is given by, σ = σE (1 + εE), where σE and εE are engineering stress and engineering strain respectively
Phosphorous can be easily recovered in the iron blast furnace
High residual stress at the surface is beneficial for fatigue properties of a material
Electrometallurgy is not involved in the extraction of __________ from its ore.
Aluminium
Tin
Lead
Both (B) & (C)
Change in volume of metals from absolute zero temperature to their melting points is
Almost same for all metals
Different for different metals
Less for low melting point metals
Less for high melting point metals
The value of 
for air & most common gases can be safely assumed to be
0.8
1
1.4
1.8
Encyclopaedia of Chemical Technology has been
Authored by Kirk Othmer
Edited by Perry and Chilton
Edited by Kirk Othmer
Authored by Perry and Chilton
Volume of blast furnace slag is about __________ times the volume of hot metal (pig iron) of the same weight
1.5
3
5
7
Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal.
Burning
Intensive oxidation
Evaporation
None of these
Ammonia gas can be dried by
PCl5
Quick lime
CaCl2
Concentrated H2SO4
Which of the following is an acidic constituent of B.F. slag?
FeO
MgO
CaO
A jet engine turbine blade is normally manufactured by
Forging
Shell moulding
Investment casting
Pressure die casting
Solidification time of a molten metal in a casting is proportional to (where, V = volume of metal & A = its surface area; in the casting)
V/A
V/A2
V2/A
V2/A2
Pearlite comprises of
87% cementite & 13% Fe
87% ferrite & 13% cementite
93.33% ferrite & 6.67% C
87% ferrite & 13% C
Which of the following materials does not form adherent oxide film on surface?
Copper
Nickel
Aluminium
Gold & silver
Which of the following is the most suitable abrasive for grinding high tensile strength materials?
Silicon carbide
Corundum
Aluminium oxide
Boron carbide
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
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
High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from __________ percent.
5 to 10
15 to 25
45 to 50
75 to 80
Coarse grained steels have
Low toughness
No tendency to distort
High density
Very high toughness
Hot extrusion process is not used for making
Cast iron pipe for domestic water supply
Aluminium curtain rods
Stainless steel tubes used in furnitures
Any of these
Steel produced from phosphatic iron is __________ in nature.
Malleable
Ductile
Brittle
Tough
Limestone is added in the blast furnace (during pig iron manufacture) to
Form slag by combining with impurities
Supply heat by undergoing exothermic reaction with impurities
Reduce the coke consumption
Reduce slag viscosity
Closeness of packing is maximum in case of __________ crystal lattice.
Face centred
Simple cubic
Body centred
None of these
Material of construction of foundry crucible is
Lead
Stainless steel
Graphite
Cast iron
Which of the following hardness tests does not measure the indentation hardness of metals and alloys?
Vickers hardness test
Shore scleroscope test
Brinell hardness test
Rockwell hardness test
Earing is a defect found in steels after the following metal working operation.
Extrusion
Rolling
Deep drawing
Wire drawing
During sensible heating of humid air
Relative humidity increases
Dew point remains constant
Dry bulb & wet bulb temperature increases
Both 'b' & 'c'
Diamagnetic materials
Are magnetised by eddy currents only
Are non-magnetic and cannot be magnetised
Are magnetised in direction opposite to the magnetic field
Can be magnetised in one direction only
The rolling process cannot be used to produce
Plates
Rods
Tubes
Wires
For infinite parallel planes having emissivities ε1 & ε2, the interchange factor for radiation from surface 1 to surface 2 is given by
