Dry saturated steam can be converted into superheated steam by
Increasing its cross-sectional area of flow
Passing it through a pressure reducing valve
Forcing it downwards through a vertical tube
None of these
Correct Answer :
B. Passing it through a pressure reducing valve
Related Questions
Annealing of cast iron
Softens it to facilitate machining
Decreases the free carbon
Increases the strength
None of these
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
What is the range of tempering temperature (°C) for most of the materials?
75-100
200-300
350-450
500-600
Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is
Black
Silver grey
Green
Yellow
The same volume of all gases is representative of their
Specific gravities
Densities
Gas characteristic constants
Molecular weights
The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C.
768
1127
1359
1480
Production of a hollow product by inflation of a tube or parison is called the __________ process.
Blow moulding
Calendaring
Extrusion
Injection
A cylindrical rod subjected to a tensile strain within the elastic limit undergoes a volume change. If the volume strain is equal to half the tensile strain, then the Poisson's ratio of the rod is
0
0.33
0.44
0.25
The most detrimental impurity in high pressure boiler feed water is
Suspended salt
Dissolved salt
Silica
Turbidity
The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is
Full annealing
Bright annealing
Patenting
None of these
Minimum number of members required to form a Public Limited Joint Stock Com-pany is
7
10
12
17
Which of the following is not a principal alloying element for the structural steel?
Molybdenum
Nickel
Manganese
Chromium
For separating small pieces of metal from engine oil of a car, the best separating technique is the
Chromatography
Evaporation
Filtration
Fractional distillation
Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about __________ percent.
1
10
30
50
Magnesium is present in
Haemoglobin
Chlorophyll
Hypo solution
None of these
Age hardening is connected with
Babbitt metal
Gun metal
Stainless steel
Duralumin
Electrochemical corrosion can occur, only if __________ is present in contact with metal.
Air
Oxygen
Liquid medium
Gaseous medium
Mho's scale of hardness, which consists of 10 standard minerals is used for the measurement of __________ hardness.
Scratch
Indentation
Dynamic
Rebound
Boiling point of water gets lowered at high altitudes (e.g., hills), because
Temperature is low
Atmospheric pressure is low
Atmospheric pressure is high
None of these
In the blast furnace, incorporation of water vapour in the blast gives the following effect.
Increases the reducing potential of the gas
Increases the flame temperature
No significant change occurs
Increases the hydrogen content in the metal
The best guide to judge the general quality of water is the measurement of its
pH value
Electrical conductivity
Turbidity
Dissolved oxygen content
__________ pipe is the most suitable for carrying sanitary drainage.
Stainless steel
Reinforced cement concrete
Cast iron
Asbestos cement
Factor of safety in machine design is defined as the ratio of ultimate stress to __________ stress.
Working
Bearing
Yield
None of these
Difference at any instant between the value of the controlled variable and the set point is called the
Deviation
Derivative time
Error ratio
Differential gap
Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.
Slip
Fracture
Winning
Dislocation
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
Identify the correct statement.
Sphlerite is zinc oxide
The first law of the thermodynamics is stated as δE = δQ - δW
Lead can be produced in a blast furnace
T. ferrooxidans is a fungus that can be used for leaching chalcopyrite
Rankine cycle comprises of two isothermal and two __________ processes.
Isobaric
Polytropic
Isentropic
None of these
Tip of the match stick contains a mixture of
K + S
K + S + K2Cr2O7
S + K2Cr2O7 + White P
None of these
__________ cannot increase the fatigue strength of a material.
Grain refining
Grain coarsening
Surface hardening
Shot peening