## Steam Boilers, Engines, Nozzles and Turbines 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 = β₂ and β₁ = α₂
α₁ < β₁ and α₂ > β₂

## Steam Boilers, Engines, Nozzles and Turbines On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by

Vertical straight line
Curved line
Horizontal straight line
Straight inclined line

## Steam Boilers, Engines, Nozzles and Turbines The best suited coal for chain or traveling grate stoker boiler is

Non-coking or free burning coal
Coking coal
Pulverized coal
High sulphur coal

## Steam Boilers, Engines, Nozzles and Turbines In order to compare the capacity of boilers, the feed water temperature and working pressure are taken as

50°C and 1.1 bar pressure
50°C and normal atmospheric pressure
100°C and normal atmospheric pressure
100°C and 1.1 bar pressure

## Steam Boilers, Engines, Nozzles and Turbines Primary air is the air used to

Transport and dry the coal
Air delivered by forced draft fan
Provide air around burners for obtaining optimum combustion
Convert CO (formed in lower zone of furnace) into CO₂ at higher zone

## Steam Boilers, Engines, Nozzles and Turbines Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?

A steam turbine develops higher speeds
The steam consumption is less
All of these
The efficiency of steam turbine is higher