Which of the following coals has the highest calorific value?
Anthracite coal
Bituminous coal
Lignite
Peat
Correct Answer :
A. Anthracite coal
Related Questions
The economiser is used in boilers to
Increase thermal efficiency of boiler
Economise on fuel
Extract heat from the exhaust flue gases
Increase flue gas temperature
In locomotive boiler, maximum steam pressure is limited to
1 kg/cm²
5 kg/cm²
10 kg/cm²
18 kg/cm²
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
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
The working pressure range for a LaMont boiler is
0.5 to 10 MN/m²
1 to 15 MN/m²
2.5 to 15 MN/m²
3.5 to 20 MN/m²
The effect of friction on the flow of steam through a nozzle is to
Decrease the mass flow rate and to increase the wetness of steam
Increase the mass flow rate and to increase the exit temperature
Decrease the mass flow rate and to decrease the wetness of steam
Increase the exit temperature without any effect on mass flow rate
An ideal regenerative cycle is
Equal to Carnot cycle
Less than Carnot cycle
More than Carnot cycle
Could be anything
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
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
When the cross-section of a nozzle __________ continuously from entrance to exit, it is called a convergent nozzle.
Increases
Decreases
Remain same
None of these
Which of the following is required for a steam condensing plant?
Condenser
Condensate pump
Air extraction pump
All of these
In a glass tube type water indicator for a boiler, one end of the tube is connected to water space and the other end is connected to
Water space also
Chimney
Steam space
Superheater
In forced circulation steam boilers, the force is applied
To draw water
To circulate water
To drain off the water
All of these
The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
A steam nozzle converts
Heat energy of steam into kinetic energy
Kinetic energy into heat energy of steam
Heat energy of steam into potential energy
Potential energy into heat energy of steam
Lancashire boiler is of
Stationary < fire tube type
Horizontal type
Natural circulation type
All of the above
Willians line for the steam engine is a straight line relationship between the steam consumption per hour and
Indicated power
Brake power
Efficiency
Pressure of steam
In a compound steam engine, the first stage of expansion is carried out in a high pressure cylinder whereas the last expansion is completed in low pressure cylinder. The diameter of high pressure cylinder is _________ the low pressure cylinder.
Equal to
Less than
More than
None of these
Which of the following is steam dial?
Non-coking bituminous coal
Brown coal
Pulverised coal
Coking bituminous coal
The ratio of brake power to the indicated power is known as
Mechanical efficiency
Overall efficiency
Indicated thermal efficiency
Brake thermal efficiency
A condenser in a steam power plant
Increases expansion ratio of steam
Reduces back pressure of steam
Reduces temperature of exhaust steam
All of these
For a Parson's reaction turbine, if α₁ and α₂ are fixed blade angles at inlet and exit respectively and β₁ and β₂ are the moving blade angles at entrance and exit respectively, then
α₁ = α₂ and β₁ = β₂
α₁ = β₁ and α₂= β₂
α₁ < β₁ and α₂ > β₂
α₁ = β₂ and β₁ = α₂
The maximum discharge of steam through a convergent-divergent nozzle depends upon
Area of nozzle at throat
Initial pressure and volume of steam
Final pressure of steam leaving the nozzle
Both (A) and (B)
In a nozzle, the effect of super-saturation is to
Decrease dryness fraction of steam
Decrease specific volume of steam
Increase the entropy
Increase the heat drop
The critical pressure gives the velocity of steam at the throat
Equal to the velocity of sound
Less than the velocity of sound
More than the velocity of sound
None of these
The pressure at which latent heat of vaporisation of water is zero, is
Below atmospheric pressure
1 kg/cm²
100 kg/cm²
225.6 kg/cm²
Efficiency of a thermal cycle increases by
Regeneration
Reheating of steam
Both (A) and (B)
Cooling of steam
The clearance in the engine cylinder
Increases the mean effective pressure
Increases the workdone
Decreases the efficiency of the engine
All of these
In case of condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the atmospheric pressure.
Equal to
Lower than
Higher than
None of these
The dry saturated steam at very low pressure, (510 kg/cm²) when throttled to atmosphere will become
Wet
Superheated
Remain dry saturated
Dry