Alkaline pyrogallate is used in Orsat's apparatus for absorption of
CO₂
CO
O₂
N₂
Correct Answer :
C. O₂
Related Questions
The maximum efficiency of a De-Laval turbine is (where α = Nozzle angle)
sin²α
cos²α
tan²α
cot²α
The efficiency of a boiler is defined as
Ratio of heat actually used in producing steam to the heat liberated in the furnace
Ratio of the mass of steam produced to the mass of total water supplied in a given time
Ratio of the heat liberated in the furnace to the heat actually used in producing steam
None of the above
The numbers of fire tubes in a Cochran boiler are
75
115
165
225
The radius of a dished head is taken approximately as
One fourth
Half
One
Two
The ratio of the actual vacuum to the ideal vacuum in a condenser is called
Condenser efficiency
Vacuum efficiency
Nozzle efficiency
Boiler efficiency
Which of the following is a fire tube boiler?
Locomotive boiler
Babcock and Wilcox boiler
Stirling boiler
All of the above
Which of the following statement is correct?
The efficiency of steam turbines is greater than steam engines
A flywheel is a must for steam turbine
The turbine blades do not change the direction of steam issuing from the nozzle
The pressure of steam, in reaction turbines, is increased in fixed blades as well as in moving blades
The critical pressure ratio (p₂/p₁) is given by
(p₂/p₁) = [2/(n - 1)] n/(n + 1)
(p₂/p₁) = [2/(n + 1)] n/(n-1)
(p₂/p₁) = [(n - 1)/2] n + (1/n)
(p₂/p₁) = [(n + 1)/2] n - (1/n)
The efficiency of the plant __________ with the mechanical draught.
Increases
Decreases
Remains constant
None of these
Carbonisation of coal is the process of
Pulverising coal in inert atmosphere
Heating wood in a limited supply of air at temperatures below 300°C
Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Binding the pulverised coal into briquettes
Expanding steam to a very low pressure (high vacuum) in steam engines is
Desirable
Economical
Essential
Uneconomical
The critical pressure ratio is given by (where p₁ = Initial pressure of steam, and p₂ = Pressure of steam at throat or critical pressure)
p₁. p₂
p₁/p₂
p₂/p₁
p₁ + p₂
When the speed of the crankshaft is between 100 r.p.m. and 250 r.p.m., the engine said to be a
Slow speed engine
Medium speed steam engine
High speed steam engine
None of these
The reheat factor is the ratio of the
Cumulative heat drop to the isentropic heat drop
Isentropic heat drop to the heat supplied
Total useful heat drop to the total isentropic heat drop
None of the above
A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are
Supplied by same manufacturer loose and assembled at site
Supplied mounted on a single base
Purchased from several parties and packed together at site
Packaged boiler does not exist
Which of the following is a water tube boiler?
Lancashire boiler
Babcock and Wilcox boiler
Locomotive boiler
Cochran boiler
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
The efficiency of reaction turbine is maximum when (where α = Angle made by the absolute velocity V at inlet)
Vb = 0.5 V cosα
Vb = V cos α
Vb = 0.5 V² cosα
Vb = V² cosα
Which is not correct statement about effect of sulphur in fuel?
It has heating value
It helps in electrostatic precipitation of ash in flue gases
It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low
It erodes furnace walls
The effect of friction in the nozzle __________ dryness fraction of steam.
Has no effect on
Decreases
Increases
None of these
The biggest size of thermal power unit operating in India is
30 MW
60 MW
100 MW
500 MW
Ultimate analysis of fuel is determination of percentage of
Carbon, hydrogen, nitrogen, sulphur, moisture
Fixed carbon, ash, volatile matter, moisture
Higher calorific value
Lower calorific value
The function of a piston rod is
To guide motion of the piston rod and to prevent it from bending
To transfer motion from the piston to the cross head
To convert heat energy of the steam into mechanical work
To exhaust steam from the cylinder at proper moment
When the cross-section of a nozzle increases continuously from entrance to exit, it is called a
Divergent nozzle
Convergent nozzle
Convergent-divergent nozzle
None of these
For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine.
Equal to
Twice
Three times
Four times
The diameter of fire tubes in Cochran boiler is of the order of
2 cm
6 cm
8 cm
12 cm
In recuperative air preheaters, the heat is transferred
From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing,
Heat is transferred by bleeding some gases from furnace
Green coal, in order to be burnt, must be
Heated sufficiently
Burnt in excess air
Heated to its ignition point
Burnt as powder
A safety valve usually employed with stationary boilers is
Lever safety valve
Dead weight safety valve
High steam and low water safety valve
All of these
The natural draught is produced by
Steam jet
Centrifugal fan
Chimney
Both (A) and (B)