An impulse turbine as compared to a reaction turbine, for a given power has _________ row of blades.
Equal
Less
More
None of these
Correct Answer :
C. More
Related Questions
In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is
0.007 bar
0.053 bar
0.06 bar
0.067 bar
Which of the following are boiler accessories?
Economiser
Superheater
Both (A) and (B)
None of these
Steam turbines are used for
Large marine propulsion
Electric power generation
Direct drive of fans, compressors, pumps
All of these
One kg of steam sample contains 0.8 kg dry steam; Its dryness fraction is
0.2
0.8
1.0
0.6
In a Tandem type compound engine, the high pressure and low pressure cylinders
Have common piston rod
Are set at 90°
Have separate piston rods
Are set in V-arrangement
The fusible plug in small boilers is located
In the drum
In the fire tubes
Above steam dome
Over the combustion chamber
Calorific value of coal is of the order of
200-400 kcal/ kg
800-1200 kcal/ kg
2000-4000 kcal/ kg
5000-8000 kcal/ kg
The function of injector used in small capacity boilers is to
Create vacuum
Inject chemical solution in feed pump
Pump water, similar to boiler feed pump
Add make up water in the system
Adiabatic process is
Essentially an isentropic process
Non-heat transfer process
Reversible process
Constant temperature process
Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of
Higher effectiveness of boiler
High calorific value coal being burnt
Fouling of heat transfer surfaces
Raising of steam temperature
The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.
10 to 15 %
15 to 20 %
20 to 30 %
30 to 40 %
A device used to increase the temperature of saturated steam without raising its pressure, is called
Blow off cock
Fusible plug
Superheater
Stop valve
The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop
Remains the same
Increases
Decreases
Is unpredictable
The diameters of fire tubes and superheater tubes in locomotive boiler are
47.5 mm, 130 mm
32.5 mm, 180 mm
65.5 mm, 210 mm
24.5 mm, 65 mm
Hard coke is produced by carburisation of coal at
Atmospheric temperature
500-600°C
700-850°C
950-1100°C
De-Laval turbines are mostly used
Where low speeds are required
For small power purposes and low speeds
For large power purposes
For small power purposes and high speeds
The behaviour of coal in a furnace is determined by
The content of sulphur
The content of ash and heating value
The proximate analysis
The exact analysis
The function of a valve rod is
To provide reciprocating motion to the slide valve
To convert reciprocating motion of the piston into rotary motion of the crank
To convert rotary motion of the crankshaft into to and fro motion of the valve rod
To provide simple harmonic motion to the D-slide valve
Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?
A steam turbine develops higher speeds
The efficiency of steam turbine is higher
The steam consumption is less
All of these
In forced recirculation type boiler,
Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation
The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in metres, and T1 = Absolute temperature of air outside the chimney in K)
T1 /88.25H
88.25H/T1
T1 /176.5H
176.5H/T1
Parson's turbine is a
Simple impulse turbine
Simple reaction turbine
Impulse-reaction turbine
None of these
One kilowatt-hour energy is equivalent to
1000 J
360 kJ
3600 kJ
3600 kW/sec
A regenerative steam cycle renders
Increased work output per unit mass of steam
Decreased work output per unit mass of steam
Increased thermal efficiency
Decreased work output per unit mass of steam as well as increased thermal efficiency
The number of water level indicators in a boiler are generally _________ in number.
One
Two
Three
Four
The diameter of fire tubes in Cochran boiler is of the order of
2 cm
6 cm
8 cm
12 cm
Primary air is the air used to
Provide air around burners for obtaining optimum combustion
Transport and dry the coal
Convert CO (formed in lower zone of furnace) into CO₂ at higher zone
Air delivered by forced draft fan
Bomb calorimeter is used to determine
Higher calorific value at constant volume
Lower calorific value at constant volume
Higher calorific value at constant pressure
Lower calorific value at constant pressure
The velocity of steam leaving the nozzle (V) is given by (where K = Nozzle coefficient or nozzle efficiency, and hd = Enthalpy or heat drop during expansion of steam in a nozzle)
V = 44.72 hd K
V = 44.72 K hd
V = 44.72 K hd
V = 44.72 K hd
The performance of a boiler is measured by the
Amount of water evaporated per hour
Steam produced in kg/h
Steam produced in kg/kg of fuel burnt
All of these