The maximum discharge through a chimney occurs when the height of chimney is
Infinitely long
Around 200 meters
Equal to the height of the hot gas column producing draught
Outside temperature is very low
Correct Answer :
C. Equal to the height of the hot gas column producing draught
Related Questions
The ultimate analysis of fuel lists
Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash
In an impulse reaction turbine, the pressure drops gradually and continuously over
Fixed blades
Moving blades
Both fixed and moving blades
None of these
The air pressure at the fuel bed is reduced below that of atmosphere by means of a fan placed at or near the bottom of the chimney to produce a draught. Such a draught is called
Natural draught
Induced draught
Forced draught
Balanced draught
The ratio of total useful heat drop to the total isentropic heat drop, is called
Stage efficiency
Internal efficiency
Rankine efficiency
None of these
A nozzle is said to be a convergent nozzle
When the cross-section of the nozzle increases continuously from entrance to exit
When the cross-section of the nozzle decreases continuously from entrance to exit
When the cross-section of the nozzle first decreases from entrance to throat and then increases from its throat to exit
None of the above
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
Water at pressure of 4 kg/cm² and 160°C temperature when exposed to atmosphere will
Boil
Flash i.e. get converted into steam
Remain as it was
Cool down
The cylindrical shell of a Lancashire boiler has diameter from
1 to 2 m
1.25 to 2.25 m
1.5 to 2.5 m
1.75 to 2.75 m
Lancashire boiler is a
Stationary fire tube boiler
Stationary water tube boiler
Water tube boiler with natural/forced circulation
Mobile fire tube boiler
The high pressure and low pressure cylinders in a Tandem type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
The function of an eccentric 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
Fusible plug for boilers is made of fusible metal containing tin, lead, and
Bismuth
Copper
Aluminium
Nickel
The amount of water evaporated in kg per kg of fuel burnt is called
Evaporative capacity of a boiler
Equivalent evaporation from and at 100° C
Boiler efficiency
None of these
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
Steam turbines may be classified according to
Direction of steam flow
Number of stages
Mode of steam action
All of these
The height of chimney in a power plant is governed by
The draft to be created
Limitation of construction facilities
Control of pollution
Quantity of flue gases to be handled
The maximum discharge through a chimney occurs when the height of chimney is
Infinitely long
Around 200 meters
Equal to the height of the hot gas column producing draught
Outside temperature is very low
Which of the following statement is correct?
The expansion of steam in a nozzle follows Rankine cycle.
The friction in the nozzle increases the dryness fraction of steam.
The pressure of steam at throat is called critical pressure.
All of the above
The velocity of whirl at outlet for an axial discharge turbine is
Minimum
Maximum
Zero
None of these
The ratio of the isentropic heat drop to the heat supplied, is called
Reheat factor
Stage efficiency
Internal efficiency
Rankine efficiency
Pick up the wrong statement about water tube boiler in comparison to fire tube boilers
Former occupies less space for same power
Rate of steam flow is more in former case
Former is used for high installed capacity
Chances of explosion are less in former case.
Which is not correct statement about the function of furnace?
To provide proper conditions for continuous complete combustion
Mix fuel with air and ignite
Separate ash from coal
Maintain heat supply to prepare and ignite the incoming fuel
Mechanical equivalent of heat for 1 kcal or Joule's equivalent is equal to
421 kg.m
421 kg.m
539 kg.m
102 kg.m
Which of the following statement is wrong?
Locomotive boiler is a water tube boiler
Water tube boilers are internally fired
Lamont boiler is a low pressure water tube boiler
All of the above
In a boiler, the heat is lost
To dry flue gases
In moisture present in the fuel
To steam formed by combustion of hydrogen per kg of fuel
All of the above
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
The rate of steam produced in Benson boiler is
100 tonnes/h
135 tonnes/h
175 tonnes/h
250 tonnes/h
The safety valve at superheater as compared to drum safety valve setting is set at
Higher value
Lower value
Same value
Any value
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
Which of the following is steam dial?
Non-coking bituminous coal
Brown coal
Pulverised coal
Coking bituminous coal