Practice Steam Boilers, Engines, Nozzles And Turbines Multiple Choice Questions Quiz-9 - MCQGeeks.com

Q.1

The chimney draught varies with

Climatic conditions
Temperature of furnace gases
Height of chimney
All of these

Q.2

Green coal, in order to be burnt, must be

Heated sufficiently
Burnt in excess air
Heated to its ignition point
Burnt as powder

Q.3

The ratio of the workdone on the blades to the energy supplied to the blades, is called

Blading efficiency
Nozzle efficiency
Gross or stage efficiency
Mechanical efficiency

Q.4

Lancashire boiler is

Stationary fire tube boiler
Internally fired boiler
Horizontal boiler
All of these

Q.5

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

Q.6

The efficiency of the plant __________ with the mechanical draught.

Increases
Decreases
Remains constant
None of these

Q.7

Which of the following is a water tube boiler?

Lancashire boiler
Babcock and Wilcox boiler
Locomotive boiler
Cochran boiler

Q.8

Which of the following is a water tube boiler?

Locomotive boiler
Cochran boiler
Cornish boiler
Babcock and Wilcox boiler

Q.9

When the total heat of steam is h kJ/kg and the sensible heat of feed water is hf1 kJ/kg, then the factor of evaporation is given by

(h - hf1)/2257
(h + hf1)/2257
(h × hf1)/2257
None of these

Q.10

The effect of super-saturation is that the

Mass of the steam discharged increases
Entropy and specific volume of the steam increases
Exit velocity of steam reduces
All of these

Q.11

Which of the following statement is wrong?

The factor of evaporation for all boilers is always greater than unity
The amount of water evaporated in kg per kg of fuel burnt is called equivalent evaporation from and at 100° C
The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called boiler efficiency
None of the above

Q.12

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

Q.13

A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are

Supplied by same manufacturer loose and assembled at site
Supplied mounted on a single base
Purchased from several parties and packed together at site
Packaged boiler does not exist

Q.14

The steam temperature with increase in load in case of a boiler fitted with radiation superheater

Increases
Decreases
Remain unaffected
First increases and then decreases

Q.15

Which of the following statement is wrong?

The critical pressure gives the velocity of steam at the throat equal to the velocity of sound
The flow in the convergent portion of the nozzle is subsonic
The flow in the divergent portion of the nozzle is supersonic
To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary

Q.16

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

Q.17

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

Q.18

Which of the following statement indicates the difference between Cornish boiler and Lancashire boiler?

Cornish boiler is a water tube boiler whereas Lancashire boiler is a fire tube boiler
Cornish boiler is a fire tube boiler whereas Lancashire boiler is a water tube boiler
Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes
Cornish boiler has two flue tubes whereas Lancashire boiler has one flue tube

Q.19

The biggest size of thermal power unit operating in India is

30 MW
60 MW
100 MW
500 MW

Q.20

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

Q.21

The ratio of the useful heat drop to the isentropic heat drop is called

Condenser efficiency
Nozzle efficiency
Boiler efficiency
Vacuum efficiency

Q.22

In recuperative air preheaters, the heat is transferred

From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing
Heat is transferred by bleeding some gases from furnace

Q.23

An air preheater is installed

Before the economiser
Before the superheater
Between the economiser and chimney
None of these

Q.24

In regenerative air preheaters, the heat is transferred

From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing
Heat is transferred by bleeding some gas from furnace

Q.25

The maximum efficiency of a reaction turbine is

2 sin²α/(1 + sin²α)
2 cos²α/(1 + cos²α)
(1 + sin²α)/2 sin²α
(1 + cos²α)/2 cos²α

Q.26

The value of the reheat factor varies from

1.02 to 1.06
1.08 to 1.10
1.2 to 1.6
1.6 to 2

Q.27

The shell of the Cochran boiler is made hemispherical

To give maximum space and strength
To withstand the pressure of steam inside the boiler
Both (A) and (B)
None of the above

Q.28

The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop

Remains the same
Increases
Decreases
Is unpredictable

Q.29

The overall efficiency of thermal power plant is

Boiler efficiency, turbine efficiency, generator efficiency
All the three above plus gas cycle efficiency
Carnot cycle efficiency
Regenerative cycle efficiency

Q.30

Mechanical equivalent of heat for 1 kcal or Joule's equivalent is equal to

421 kg.m
421 kg.m
539 kg.m
102 kg.m

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