The velocity of whirl at outlet for an axial discharge turbine is
Minimum
Maximum
Zero
None of these
Correct Answer :
C. Zero
Related Questions
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
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
The object of producing draught in a boiler is
To provide an adequate supply of air for the fuel combustion
To exhaust the gases of combustion from the combustion chamber
To discharge the gases of combustion to the atmosphere through the chimney
All of the above
In a reaction turbine, when steam flows through the fixed blades,
Pressure increases while velocity decreases
Pressure decreases while velocity increases
Pressure and velocity both decreases
Pressure and velocity both increases
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)
When the circulation of water, in a boiler, is by convection currents which are set up during the heating of water, then the boiler is known as
Internally fired boiler
Externally fired boiler
Natural circulation boiler
Forced circulation boiler
The ratio of the workdone on the blades to the energy supplied to the blades, is called
Blading efficiency
Nozzle efficiency
Gross or stage efficiency
Mechanical efficiency
Which of the following boilers is best suited to meet fluctuating demands?
Babcock and Wilcox
Locomotive
Lancashire
Cochran
Fire tube boilers are limited to a maximum working pressure of
0.17 MN/m²
1.7 MN/m²
17 MN/m²
170 MN/m²
Which of the following compound steam engine requires a smaller flywheel?
Receiver type
Tandem type
Woolf type
All of these
The heat balance sheet for the boiler shows the
Complete account of heat supplied by 1 kg of dry fuel and the heat consumed
Moisture present in the fuel
Steam formed by combustion of hydrogen per kg of fuel
All of the above
In natural circulation 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 critical pressure at which latent heat of vaporisation is zero is
225.65 kgf/ cm²
273 kgf/ cm²
100 kgf/ cm²
1 kgf/ cm²
The ratio of heat utilised to produce steam and the heat liberated in furnace is known as
Boiler effectiveness
Boiler evaporative capacity
Factor of evaporation
Boiler efficiency
A compound steam engine in which piston rods of high pressure and low pressure cylinders are attached to two different cranks set at 90° to each other, is called
Receiver type compound engine
Tandem type compound engine
Woolf type compound engine
Both (A) and (B)
The critical pressure ratio for initially wet steam is
0.546
0.577
0.582
0.601
Reheating of steam under ideal conditions takes place at constant
Entropy
Enthalpy
Pressure
Temperature
Adiabatic process is
Essentially an isentropic process
Non-heat transfer process
Reversible process
Constant temperature process
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
In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is __________ the relative velocity of steam at inlet tip of the blade.
Equal to
Less than
Greater than
None of these
With increase in load, convection superheater has
Drooping characteristic
Linear characteristic
Rising characteristic
Flat characteristic
The balanced draft furnace is one using
Induced draft fan and chimney
Induced draft fan and forced draft fan
Forced draft fan and chimney
Any one of the above
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 discharge is __________ at critical pressure.
Zero
Minimum
Maximum
None of these
The dry saturated steam at very high pressure (150200 kg/cm²) when throttled to atmosphere will become
Wet
Superheated
Remain dry saturated
Dry
If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
Throttling calorimeter
Separating calorimeter
Combined separating and throttling calorimeter
Bucket calorimeter
The change in internal energy in steam engines equals to
Work done during the Rankine cycle
Work done during compression
Work done during adiabatic expansion
Change in enthalpy
The diameter of Cornish boiler is of the order of
12 m
1.52.5 m
23 m
2.53.5 m
A closed vessel made of steel and used for the generation of steam is called a
Steam boiler
Steam turbine
Steam condenser
Steam injector
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