An ideal regenerative cycle is
Equal to Carnot cycle
Less than Carnot cycle
More than Carnot cycle
Could be anything
Correct Answer :
B. Less than Carnot cycle
Related Questions
The diameter of superheated tubes in a locomotive boiler is
13 mm
31 mm
130 mm
230 mm
In water tube boilers
Water passes through the tubes which are surrounded by flames and hot gases
The flames and hot gases pass through the tubes which are surrounded by water
Forced circulation takes place
None of these
The major axis of elliptical manholes on the shell should be provided
Longitudinally
Circumferentially
On dished end
Anywhere
The diagram efficiency is the ratio of
Workdone on the blades to the energy supplied to the blades
Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
None of the above
In an ideal impulse turbine, the
Absolute velocity at the inlet of moving blade is equal to that at the outlet
Relative velocity at the inlet of the moving blade is equal to that at the outlet
Axial velocity at inlet is equal to that at the outlet
Whirl velocity at inlet is equal to that at the outlet
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 density of supersaturated steam is about __________ that of the ordinary saturated vapour at the corresponding pressure.
Same as
2 times
4 times
8 times
Steam turbines may be classified according to
Direction of steam flow
Number of stages
Mode of steam action
All of these
Reheating of steam in a turbine
Increases the workdone through the turbine
Increases the efficiency of the turbine
Reduces wear on the blades
All of these
The increase in pressure
Lowers the boiling point of a liquid
Raises the boiling point of a liquid
Does not affects the boiling point of a liquid
Reduces its volume
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
Which of the following boiler is best suited to meet the fluctuating demand of steam?
Locomotive boiler
Lancashire boiler
Cornish boiler
Babcock and Wilcox boiler
The nozzle efficiency is the ratio of
Workdone on the blades to the energy supplied to the blades
Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
None of the above
The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be
0.4
0.56
0.67
1.67
Steam turbines are used for
Large marine propulsion
Electric power generation
Direct drive of fans, compressors, pumps
All of these
The three Ts for good combustion are
Temperature, time, and turbulence
Total air, true fuel, and turbulence
Thorough mixing, total air and temperature
Total air, time, and temperature
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
A device used to heat feed water by utilising the heat in me exhaust flue gases before leaving through the chimney, is known as
Economiser
Fusible plug
Superheater
Stop valve
Which of the following gases has the highest calorific value?
Producer gas
Coal gas
Water gas
Blast furnace gas
In an impulse turbine
The steam is expanded in nozzles only and there is a pressure drop and heat drop
The steam is expanded both in fixed and moving blades continuously
The steam is expanded in moving blades only
The pressure and temperature of steam remains constant
The discharge of steam in a convergent-divergent nozzle __________ after the throat (i.e. in the divergent portion of the nozzle)
Remains constant
Decreases
Increases
None of these
The best suited coal for chain or travelling grate stoker boiler is
Coking coal
Non-coking or free burning coal
Pulverised coal
High sulphur coal
The maximum heat loss is a boiler occurs due to
Moisture in fuel
Dry flue gases
Steam formation
Unburnt carbon
The fusible plug in small boilers is located
In the drum
In the fire tubes
Above steam dome
Over the combustion chamber
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
While steam expands in turbines, theoretically the entropy
Remains constant
Increases
Decreases
Behaves unpredictably
The velocity of flue gases (V) through the chimney under a static draught of (H') metres is given by
V = 2g H'
V = 2g/H'
V = H'/2g
V = 2gH'
De-Laval turbine is a
Single rotor impulse turbine
Multi-rotor impulse turbine
Impulse reaction turbine
None of these
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 number of water level indicators in a boiler are generally _________ in number.
One
Two
Three
Four