Practice Steam Boilers, Engines, Nozzles And Turbines Multiple Choice Questions Quiz-7 - MCQGeeks.com

Q.1

A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.

Blow off cock
Fusible plug
Stop valve
Safety valve

Q.2

At very low temperature, the melting and boiling temperatures become equal. This temperature is

373°K
273.16°K
303°K
0°K

Q.3

Carbonization of coal is the process of

Pulverizing 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 pulverized coal into briquettes

Q.4

Stoichiometric quantity of air is the

Air present in atmosphere at NTP conditions
Air required for complete combustion of fuel with no excess air
Air required for optimum combustion so as to have reasonable excess air
Air required to convert CO into CO₂

Q.5

Which is not correct statement about pulverized fuel firing?

High burning rate is possible
Heat release can be easily controlled
Fuel burns economically
It is the best technique for burning high ash content fuel having low fusion ash

Q.6

When the inlet pressure of steam is equal to the exit pressure, then

There is a pressure drop in the nozzle
Fluid flows through the nozzle
Pressure drops and fluid flows through the nozzle
There is no pressure drop and fluid does not flow through the nozzle

Q.7

A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as

Blow off cock
Fusible plug
Superheater
Stop valve

Q.8

Boiler H.P. is defined as the

Steam evaporation rate per kg of fuel fired
Work done in evaporating 1 kg of steam per hour from and at 100°C into dry saturated steam
The evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam
Work done by 1 kg of steam at saturation condition

Q.9

The relative efficiency is defined as the

Ratio of thermal efficiency to Rankine efficiency
Ratio of brake power to the indicated power
Ratio of heat equivalent to indicated power to the energy supplied in steam
Product of thermal efficiency and Rankine efficiency

Q.10

The indicated thermal efficiency is defined as the

Ratio of thermal efficiency to the Rankine efficiency
Ratio of brake power to the indicated power
Ratio of heat equivalent to indicated power to the energy supplied in steam
Product of thermal efficiency and Rankine efficiency

Q.11

On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by

Horizontal straight line
Vertical straight line
Straight inclined line
Curved line

Q.12

A fusible plug is fitted in small boilers in order to

Avoid excessive build up of pressure
Avoid explosion
Extinguish fire if water level in the boiler falls below alarming limit
Control steam dome

Q.13

Presence of moisture in fuel oil would

Keep the burner tips cool
Aid in proper combustion
Because sputtering, possibly extinguishing flame
Clean the nozzles

Q.14

Which of the following varieties of coals is mostly used in steam boilers?

Non-coking bituminous coal
Brown coal
Peat
None of the above

Q.15

Steam turbines are used for

Large marine propulsion
Electric power generation
Direct drive of fans, compressors, pumps
All of these

Q.16

A single acting steam engine produces __________ power than that of double acting steam engine.

Equal
Half
Double
Four times

Q.17

During storage, the heating value of coal

Increases
Decreases
Remain constant
May increase or decrease depending upon the method of storage

Q.18

For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine.

Equal to
Twice
Three times
Four times

Q.19

The equivalent evaporation is defined as

The ratio of heat actually used in producing the steam to the heat liberated in the furnace
The amount of water evaporated or steam produced in kg per kg of fuel burnt
The amount of water evaporated from and at 100°C into dry and saturated steam
The evaporation of 15.653 kg of water per hour from and at 100°C

Q.20

A safety valve usually employed with stationary boilers is

Lever safety valve
Dead weight safety valve
High steam and low water safety valve
All of these

Q.21

In locomotives, the draught is produced by

Chimney
Induced draft fan
Both combined (A) and (B)
Steam jet draught

Q.22

The process of maintaining the speed of the turbine constant for various load conditions, is known as

Bleeding
Reheating
Governing
None of these

Q.23

In designing air preheaters, the important design consideration is that

Approach temperature should be as low as possible
Handling and maintenance should be easier
Heat transfer area should be optimum
Stack gases should not be cooled to the dew point

Q.24

Which of the following are boiler accessories?

Economizer
Superheater
Both (A) and (B)
None of these

Q.25

In a reaction turbine, when steam flows through the moving blades,

Pressure increases while velocity decreases
Pressure decreases while velocity increases
Pressure and velocity both decreases
Pressure and velocity both increases

Q.26

The selection of type and size of a steam boiler depends upon

The power required and working pressure
The geographical position of the power house
The fuel and water available
All of the above

Q.27

The major axis of elliptical manholes on the shell should be provided

Longitudinally
Circumferentially
On dished end
Anywhere

Q.28

In water wall furnace, the heat is transferred to the water walls by

Convection
Radiation
Conduction
Radiation and conduction

Q.29

The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is

Less
More
Equal
May be less or more depending on temperature

Q.30

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

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