Out of the following, the __________ pipe has the least corrosion resistance.
Mild steel
Copper
Cast iron
Wrought iron
Correct Answer :
D. Wrought iron
Related Questions
Gratings is associated with the measurement of
Linear displacement
Concavity/convexity
Surface texture
Flatness
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
Hydro-cyclone is a
Crusher
wet classifier
Dry classifier
Magnetic separator
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
Which of the, following is not associated with the functioning of a petrol engine?
Compression ignition system
Spark plug
Carburettor
Otto cycle
Induced draft fans provided in large thermal power plant boilers have __________ blades.
Forward curved
Backward curved
Double curved
Radial or straight
Boiler tube size is specified by its thickness and __________ diameter.
Outside
Inside
Mean
None of these
Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is
Very low which prevents their ignition by compression
Very high which prevents their ignition by compression
Zero
None of these
CANDU type nuclear reactor using natural uranium as fuel is the extensively used nuclear reactor because of the fact that the
Specific fuel consumption is very low due to the use of heavy water
Fuel cost is much lower than that used in pressurised water or boiling water reactor
Heavy water is used both as coolant as well as moderator
Both 'b' & 'c'
In case of brasses, with decreasing zinc percentage and increasing copper percentage, its __________ increases.
Percentage elongation
Brinell hardness
Tensile strength
All 'a', 'b' & 'c'
In case of simple harmonic motion, displacement is proportional to the
Velocity
Acceleration
Both (A) & (B)
Neither (A) nor (B)
A high pressure boiler generates steam at a pressure greater than __________ kg/cm2.
10
30
50
80
Ceramic compounds as compared to metallic compounds
Crystallise faster
Resist greater tensile stress at room temperature
Have higher melting temperature
Are better conductor of electricity at higher temperature
Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature.
Copper
Steel
Aluminium
Brass
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
The Al2O3 content of cryolite in Hall- Heroult cell is maintained between __________ percent.
2-5
18-20
12-15
6-12
Pick out the wrong statement.
For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1
For calculating forces and efficiency of riveted joint, either rivet diameter or rivet hole diameter is used in case of pressure vessel and in structural work
Longitudinal joint is normally made butt joint to maintain the circularity of the vessel
Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
Specific gravity of hot metal (pig iron) is __________ times that of the blast furnace slag.
2
3
0.8
6
Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans?
Emissivity of pipe surface
Diameter & length of the pipe
Temperature of hot pipe surface & that of air in the room
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
For infinite parallel planes having emissivities ε1 & ε2, the interchange factor for radiation from surface 1 to surface 2 is given by
Which of the following gases cause global warming?
Carbon monoxide
Carbon dioxide
Nitrogen
Ozone
Austempering of steel requires it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to
Sorbite
Bainite
Martensite
Troostite
Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?
p
2 p
0.5 p
0.25 p
Liquor poisoning generally occurs due to the presence of __________ in it.
Ethyl alcohol
Impurities
Methyl alcohol
Carbonic acid
Which of the following materials has the poorest electrical conductivity?
Carbon
Aluminium
Silver
Stainless steel
While the bin cards are used in the effective stores management, the queuing theory is associated with the __________ time.
Waiting
Idle
Inspection
Tool replacement
Which of the following is the most suitable abrasive for grinding high tensile strength materials?
Silicon carbide
Corundum
Aluminium oxide
Boron carbide
Hydrogen can be
Used in I.C. engines as fuel
Liquefied & stored under cryogenic conditions
Produced by electrolysis of water
All (A), (B) & (C)
Alloy powder manufactured by the following process have spherical shapes.
Electrochemical deposition
Gaseous reduction
Atomisation
Mechanical attrition