Home
Current Affairs January 2024

What is the correct answer?

4

An air preheater

A. Increases evaporative capacity of the boiler

B. Increases the efficiency of the boiler

C. Enables low grade fuel to be burnt

D. All of the above

Correct Answer :

D. All of the above


Related Questions

What is the correct answer?

4

The economiser is used in boilers to

A. Increase thermal efficiency of boiler

B. Economise on fuel

C. Extract heat from the exhaust flue gases

D. Increase flue gas temperature

What is the correct answer?

4

The number of water level indicators in a boiler are generally _________ in number.

A. One

B. Two

C. Three

D. Four

What is the correct answer?

4

In a reaction turbine

A. The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades

B. The expansion of steam takes place partly in the fixed blades and partly in the moving blades

C. The steam is expanded from a high pressure to a condenser pressure in one or more nozzles

D. The pressure and temperature of steam remains constant

What is the correct answer?

4

In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be

A. 3.3 bar

B. 5.46 bar

C. 8.2 bar

D. 9.9 bar

What is the correct answer?

4

Fusible plug for boilers is made of fusible metal containing tin, lead, and

A. Bismuth

B. Copper

C. Aluminium

D. Nickel

What is the correct answer?

4

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

A. Convection

B. Radiation

C. Conduction

D. Radiation and conduction

What is the correct answer?

4

Pulverised fuel is used for

A. Better burning

B. More calorific value

C. Less radiation loss

D. Medium sized units

What is the correct answer?

4

The mechanical draught _________ with the amount of smoke.

A. Increases

B. Decreases

C. Does not effect

D. None of these

What is the correct answer?

4

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.

A. Blow off cock

B. Fusible plug

C. Stop valve

D. Safety valve

What is the correct answer?

4

Sulphur content of fuels is very important to the plant operators because it

A. Has high heating value

B. Retards electric precipitation

C. Promotes complete combustion

D. Has highly corrosive effect

What is the correct answer?

4

Pick up the correct statement as regards Cornish boiler and Lancashire boiler

A. Cornish is fire tube and Lancashire is water tube

B. Cornish is water tube and Lancashire is fire tube

C. Cornish has two fire tubes and Lancashire has one

D. Lancashire has two fire tubes and Cornish has one

What is the correct answer?

4

A device used to increase the temperature of saturated steam without raising its pressure, is called

A. Blow off cock

B. Fusible plug

C. Superheater

D. Stop valve

What is the correct answer?

4

The effect of friction in the nozzle __________ dryness fraction of steam.

A. Has no effect on

B. Decreases

C. Increases

D. None of these

What is the correct answer?

4

Cochran boiler is a

A. Horizontal fire tube boiler

B. Horizontal water tube boiler

C. Vertical water tube boiler

D. Vertical fire tube boiler

What is the correct answer?

4

The length of Cornish boiler varies from

A. 2 to 4.5 m

B. 3 to 5 m

C. 5 to 7.5 m

D. 7 to 9 m

What is the correct answer?

4

The feed check valve is used in order to

A. Regulate flow of boiler water

B. Check level of water in boiler drum

C. Recirculate unwanted feed water

D. Allow high pressure feed water to flow to drum and not allow reverse flow to take place

What is the correct answer?

4

The discharge is __________ at critical pressure.

A. Zero

B. Minimum

C. Maximum

D. None of these

What is the correct answer?

4

The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in metres, and T1 = Absolute temperature of air outside the chimney in K)

A. T1 /88.25H

B. 88.25H/T1

C. T1 /176.5H

D. 176.5H/T1

What is the correct answer?

4

During storage, the heating value of coal

A. Increases

B. Decreases

C. Remain constant

D. May increase or decrease depending upon the method of storage

What is the correct answer?

4

Stage efficiency is also known as

A. Diagram efficiency

B. Nozzle efficiency

C. Gross efficiency

D. None of these

What is the correct answer?

4

The chimney draught varies with

A. Climatic conditions

B. Temperature of furnace gases

C. Height of chimney

D. All of these

What is the correct answer?

4

The critical pressure ratio for initially dry saturated steam is

A. 0.546

B. 0.577

C. 0.582

D. 0.601

What is the correct answer?

4

The change in internal energy in steam engines equals to

A. Work done during the Rankine cycle

B. Work done during compression

C. Work done during adiabatic expansion

D. Change in enthalpy

What is the correct answer?

4

Water and sediment in fuel oil can be removed by

A. Heating the oil in the settling tanks

B. Cooling the oil in the settling tanks

C. Burning the oil

D. Suspension

What is the correct answer?

4

Pick up the wrong statement about water tube boiler in comparison to fire tube boilers

A. Former occupies less space for same power

B. Rate of steam flow is more in former case

C. Former is used for high installed capacity

D. Chances of explosion are less in former case.

What is the correct answer?

4

The shell diameter of a Locomotive boiler is

A. 1 m

B. 1.5 m

C. 2 m

D. 2.5 m

What is the correct answer?

4

Which of the following statement is correct for a compound steam engine?

A. The cost of the engine, for the same power and economy, is more than that of a simple steam engine.

B. The forces in the working parts are increased as the forces are distributed over more parts.

C. The ratio of expansion is reduced, thus reducing the length of stroke.

D. The temperature range per cylinder is increased, with corresponding increase in condensation.

What is the correct answer?

4

Expanding steam to a very low pressure (high vacuum) in steam engines is

A. Desirable

B. Economical

C. Essential

D. Uneconomical

What is the correct answer?

4

The ratio of the actual vacuum to the ideal vacuum in a condenser is called

A. Condenser efficiency

B. Vacuum efficiency

C. Nozzle efficiency

D. Boiler efficiency

What is the correct answer?

4

The critical pressure at which latent heat of vaporisation is zero is

A. 225.65 kgf/ cm²

B. 273 kgf/ cm²

C. 100 kgf/ cm²

D. 1 kgf/ cm²