Which of the following is not a principal alloying element for the structural steel?
Molybdenum
Nickel
Manganese
Chromium
Correct Answer :
A. Molybdenum
Related Questions
Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling.
Film
Nucleate
Transition
All modes of
Transformer cores are normally made from
Soft ferrites
High purity iron
Grain oriented Fe-Si alloy
Al-Ni-Co alloy
Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity.
300
800
1400
2000
Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process?
Galvanising
Tinning
Sherardizing
None of these
__________ joint is usually used for joining cast iron pipes mostly used for temporary pipelines, where it may be necessary to dismantle & reassemble the pipeline very frequently.
Collar
Flanged
Bell and Spigot
Expansion
'GASOHOL' widely used in Brazil as a motor fuel is a mixture of alcohol and
Petrol
LPG
Light hydrocarbon gases (e.g. butane or propane)
None of these
The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the 'Curie point', which is __________ °C.
768
908
1400
1539
For grinding of softer materials, the grinding wheel should have __________ grain size.
Finer
Coarser
Medium
Any type of
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
The surface tension of a liquid, at critical temperature is
Indeterminate
Zero
Infinity
Same as that at any other temperature
When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the
Partial pressure of water vapour is less than the total pressure
Humidity is < 100% & dew point temperature of air has not reached
Dew point temperature of air has not reached & air is not saturated fully
Air is fully saturated
The main charge in blast furnace is usually
Iron ore & coke
Iron ore, coke & air
Limestone, coke & iron ore
Limestone, sand & iron ore
Out of the following, the most malleable material is
Copper
Aluminium
Wrought iron
Lead
For the Stoke's law to be valid in the case of a falling sphere in a fluid, the
Reynolds number (based on sphere diameter) should be < 1
Flow around the sphere should be in turbulent region
Sphere must be metallic
Fluid density should be constant
The atmospheric temperature during melting of ice/snow (in the atmosphere)
Decreases
Increases
Remain same
May increase or decrease; depends on the altitude where snow melts
Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
White
Cast
Wrought
Pig
The excess air required for the combustion of pulverised coal is of the order of about __________ percent.
5
15
30
45
The friction factor for the turbulent fluid flow in a rough pipe does not depend upon the
Pipe roughness & pipe diameter
Fluid velocity
Type of flowing fluid
Both 'b' & 'c'
Material of construction of the electrode used in the electric resistance welding is
Stainless steel
Graphite
Copper
Steel
Increasing sulphur content in pig iron tends to make it
Soft
Hard
Tough
Ductile & malleable
The units of the rate constant for a second order reaction are
Which of the following materials has the least scrap value?
Aluminium
Stainless steel
Brass
Copper
Viscoelastic behaviour is observed in __________ materials.
Non-crystalline organic polymeric
Ceramic
All crystalline
All amorphous
Speed of a submarine in deep sea & that of an aeroplane is measured by a/an
Pitot tube
Hot wire anemometer
Rotameter
Stroboscope
Maximum consumption of limestone is in the __________ industry.
Iron and steel
Cement
Glass
Fertiliser
Cemented carbide tools are not suitable for cutting
Aluminium
Brass
Cast iron
Steel
In an eutectic system, two elements are completely
Soluble in solid state
Insoluble in liquid state
Insoluble in both solid & liquid state
Soluble in liquid state
All the atoms of the world comprise of electrons, proton & neutron except that of __________ atom in which neutron is absent.
Deuterium
Hydrogen
Neon
Helium
Wood is a/an __________ material.
Amorphous
Cellular
Homogeneous
Granular
Oxide layer formed on the non-ferrous metal surface after its annealing is
Removed by acid pickling
Hammered into the surface
Removed with coarse emery cloth
Left as such to protect the surface