The bituminous coal is no caking if its carbon content is
78-81 %
81-85 %
85-90 %
90-95 %
Correct Answer :
A. 78-81 %
Related Questions
Cut-off ratio is the ratio of
Swept volume to the volume at cut-off
Volume at cut-off to the clearance volume
Volume at cut-off to the swept volume
Clearance volume to the volume at cut-off
The friction in the nozzle __________ exit velocity of steam.
Has no effect on
Decreases
Increases
None of these
The length of Lancashire boiler varies from
5 to 6 m
6 to 7 m
7.25 to 9 m
9 to 10 m
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 wrong?
The mechanical draught reduces the height of chimney.
The natural draught reduces the fuel consumption.
A balanced draught is a combination of induced and forced draught.
All 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
The theoretical indicator diagram of a simple steam engine is based upon the assumption that
There is no pressure drop due to condensation
Steam is admitted at boiler pressure and exhausted at condenser pressure
The expansion (or compression) of the steam is hyperbolic
All of the above
The efficiency of an impulse turbine is maximum when (where Vb = Blade speed, V = Absolute velocity of steam entering the blade, and α = Nozzle angle)
Vb = 0.5 V cosα
Vb = V cosα
Vb = 0.5 V² cosα
Vb = V² cosα
The artificial draught is produced by
Steam jet
Centrifugal fan
Chimney
Both (A) and (B)
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
The number of flue tubes in Lancashire boiler is
Zero
One
Two
Four
The main object of a boiler trial is
To determine the generating capacity of the boiler
To determine the thermal efficiency of the boiler when working at a definite pressure
To prepare heat balance sheet for the boiler
All of the above
The velocity of whirl at outlet for an axial discharge turbine is
Minimum
Maximum
Zero
None of these
The diameter of Cornish boiler is of the order of
12 m
1.52.5 m
23 m
2.53.5 m
The device attached to the steam chest for preventing explosions due to excessive internal pressure of steam is called
Safety valve
Water level indicator
Pressure gauge
Fusible plug
A binary vapour plant consists of
Steam turbine
Steam condenser
Mercury boiler
All of these
Feed water conditioning in thermal power plants in done to
Reduce hardness and for removal of solids
Increase efficiency of thermal power plant
Increase heat transfer rate
Increase steam parameters
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 cylinder dimensions of a compound engine may be designed on the basis of
Equal power developed in each cylinder for uniform turning moment
Equal initial piston loads on all pistons for obtaining same size of piston rod, connecting rod etc. for all cylinders
Equal temperature drop in each cylinder for economy of steam
All of the above
The capacity of induced draft fan compared to forced draft fan in a boiler is
Same
More
Less
Less or more depending on size of boiler
Film boiling occurs at
Very low pressure
Atmospheric pressures
Medium pressures
Very high pressures
Thermal efficiency of well maintained boiler will be of the order
40 %
50 %
75 %
90 %
Water and sediment in fuel oil can be removed by
Heating the oil in the settling tanks
Cooling the oil in the settling tanks
Burning the oil
Suspension
Which of the following is not a boiler mounting?
Blow off cock
Feed check valve
Economiser
Fusible plug
The flow of steam is supersonic
At the entrance to the nozzle
At the throat of the nozzle
In the convergent portion of the nozzle
In the divergent portion of the nozzle
In a throttling process
Heat transfer takes place
Work is done by the expanding steam
Internal energy of steam changes
None of the above
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
Which of the following statement is correct for a compound steam engine?
The cost of the engine, for the same power and economy, is more than that of a simple steam engine.
The forces in the working parts are increased as the forces are distributed over more parts.
The ratio of expansion is reduced, thus reducing the length of stroke.
The temperature range per cylinder is increased, with corresponding increase in condensation.
With increase in load, convection superheater has
Drooping characteristic
Linear characteristic
Rising characteristic
Flat characteristic
Lancashire boiler is of
Stationary < fire tube type
Horizontal type
Natural circulation type
All of the above