All steam engines work on
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
None of these
Correct Answer :
C. Second law of thermodynamics
Related Questions
The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure.
Equal to
Less than
Higher than
None of these
In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be
3.3 bar
5.46 bar
8.2 bar
9.9 bar
The length of shell of a Locomotive boiler is
1 m
2 m
3 m
4 m
The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
Equivalent evaporation is the amount of water evaporated in a boiler from and at
0°C
100°C
Saturation temperature at given pressure
Room temperature
The equivalent evaporation of a boiler is a measure to compare
The given boiler with the model
The two different boilers of the same make
Two different makes of boilers operating under the same operating conditions
Any type of boilers operating under any conditions
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
The expansion of steam in a nozzle follows
Carnot cycle
Rankine cycle
Joule cycle
Stirling cycle
A device used to increase the temperature of saturated steam without raising its pressure, is called
Blow off cock
Fusible plug
Superheater
Stop valve
Willian's law states that the steam consumption per hour provided with a throttled governor is proportional to (where I.P. = Indicated power)
1/(I.P)
1/(I.P)²
I.P.
(I.P.)²
The specific heat of superheated steam in kcal/kg is generally of the order of
0.1
0.3
0.5
0.8
A steam turbine, in which a part of the steam after partial expansion, is used for process heating and the remaining steam is further expanded for power generation, is known as
Back pressure turbine
Pass out turbine
Low pressure turbine
Impulse turbine
Alkaline pyrogallate is used in Orsat's apparatus for absorption of
CO₂
CO
O₂
N₂
In an impulse turbine, steam expands
Wholly in blades
Wholly in nozzle
Partly in the nozzle and partly in blades
None of these
In a receiver 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
When the speed of the engine is controlled by means of a valve in a steam pipe, which regulates the pressure of steam entering the engine, then the governing is known as
Throttle governing
Cut-off governing
By-pass governing
None of these
The high steam and low water safety valve is not used in
Cochran boiler
Cornish boiler
Lancashire boiler
Locomotive boiler
For water, at pressures below atmospheric;
Melting point rises slightly and boiling point drops markedly
Melting point rises markedly and boiling point drops markedly
Melting point drops slightly and boiling point drops markedly
Melting point drops slightly and boiling point drops slightly
Steam in water tube boiler as compared to fire tube boiler
Can be raised rapidly
Is raised at slower rate
Is raised at same rate
Could be raised at fast/slow rate depending on design
A stage, in reaction turbine, is represented by
Number of casing
Number of entries of steam
Number of exits of steam
Each row of blades
The critical pressure ratio for gases is
0.528
0.546
0.577
0.582
An air preheater is installed
Before the economiser
Before the superheater
Between the economiser and chimney
None of these
The heat loss in a boiler takes place in the form of
Heat carried away by flue gases
Heat carried away by ash
Moisture present in fuel and steam formed by combustion of hydrogen in fuel
All of the above
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 length of Cornish boiler varies from
2 to 4.5 m
3 to 5 m
5 to 7.5 m
7 to 9 m
Over fire burning is the phenomenon of
Supply of excess, air
Supply of excess coal
Burning CO and unburnts in upper zone of furnace by supplying more air
Fuel bed firing
Blading efficiency is also known as
Stage efficiency
Diagram efficiency
Nozzle efficiency
None of these
The diameter of flue tube in a Cornish boiler is _________ that of the shell.
One-fourth
One-third
Two-fifth
Three-fifth
Proximate 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 specific volume of steam with increase in pressure decreases
Linearly
Slowly first and then rapidly
Rapidly first and then slowly
Inversely