Home
Current Affairs January 2024

What is the correct answer?

4

Carbonisation of coal is the process of

A. Pulverising coal in inert atmosphere

B. Heating wood in a limited supply of air at temperatures below 300°C

C. Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel

D. Binding the pulverised coal into briquettes

Correct Answer :

C. Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel


Related Questions

What is the correct answer?

4

The diameter of Cornish boiler varies from

A. 0.5 to 1 m

B. 1 to 2 m

C. 1.25 to 2.5 m

D. 2 to 3 m

What is the correct answer?

4

Incomplete combustion can be best judged by

A. Smoky chimney exit

B. Excess air in flue gases

C. Measuring carbon monoxide in flue gases

D. Measuring temperature of flue gases at exit of furnace

What is the correct answer?

4

The stage efficiency (ηS) is given by (where ηB = Blading efficiency, and ηN = Nozzle efficiency)

A. ηS = ηB × ηN

B. ηS = ηB / ηN

C. ηS = ηN / ηB

D. None of these

What is the correct answer?

4

In a single acting steam engine

A. The steam is admitted on one side of the piston and one working stroke is produced during each revolution of the crankshaft

B. The steam is admitted, in turn, on both sides of the piston and one working stroke is produced during each revolution of the crankshaft

C. The steam is admitted on one side of the piston and two working strokes are produced during each revolution of the crankshaft

D. The steam is admitted, in turn, on both sides of the piston and two working strokes are produced during each revolution of the crankshaft

What is the correct answer?

4

Presence of moisture in fuel oil would

A. Keep the burner tips cool

B. Aid in proper combustion

C. Because sputtering, possibly extinguishing flame

D. Clean the nozzles

What is the correct answer?

4

The function of a safety valve is

A. To blow off steam when the pressure of steam inside the boiler exceeds the working pressure

B. To indicate the water level inside the boiler to an observer

C. To measure pressure of steam inside the steam boiler

D. None of the above

What is the correct answer?

4

Secondary air is the air used to

A. Provide air around burners for obtaining optimum combustion

B. Transport and dry the coal

C. Convert CO (formed in lower zone of furnace) into CO₂ at higher zone

D. Air delivered by induced draft fan

What is the correct answer?

4

The high pressure boiler is one, which produces steam at a pressure more than

A. Atmospheric pressure

B. 5 kg/cm²

C. 10 kg/cm²

D. 7580 kg/cm²

What is the correct answer?

4

During polytropic process

A. Heat transfer takes place across cylinder walls

B. Work is done

C. Steam may be wet, dry or superheated after expansion

D. All of the above

What is the correct answer?

4

Reheating of steam in a turbine

A. Increases the workdone through the turbine

B. Increases the efficiency of the turbine

C. Reduces wear on the blades

D. All of these

What is the correct answer?

4

Maximum energy loss in a boiler occurs due to

A. Unburnt carbon in ash

B. Incomplete combustion

C. Ash content

D. Flue gases

What is the correct answer?

4

Water tube boilers are those in which

A. Flue gases pass through tubes and water around it

B. Water passes through the tubes and flue gases around it

C. Work is done during adiabatic expansion

D. Change in enthalpy

What is the correct answer?

4

The radius of a dished head is taken approximately as

A. One fourth

B. Half

C. One

D. Two

What is the correct answer?

4

The maximum discharge of steam through a convergent-divergent nozzle depends upon

A. Area of nozzle at throat

B. Initial pressure and volume of steam

C. Final pressure of steam leaving the nozzle

D. Both (A) and (B)

What is the correct answer?

4

Pick up the wrong statement about critical condition of steam

A. Latent heat is zero

B. Liquid directly becomes steam

C. Specific volume of steam and liquid is same

D. This is the maximum pressure limit

What is the correct answer?

4

The behaviour of coal in a furnace is determined by

A. The content of sulphur

B. The content of ash and heating value

C. The proximate analysis

D. The exact analysis

What is the correct answer?

4

The amount of water evaporated in kg per kg of fuel burnt is called

A. Evaporative capacity of a boiler

B. Equivalent evaporation from and at 100° C

C. Boiler efficiency

D. None of these

What is the correct answer?

4

The balanced draft furnace is one using

A. Induced draft fan and chimney

B. Induced draft fan and forced draft fan

C. Forced draft fan and chimney

D. Any one of the above

What is the correct answer?

4

Which of the following statement is wrong?

A. The critical pressure gives the velocity of steam at the throat equal to the velocity of sound.

B. The flow in the convergent portion of the nozzle is subsonic.

C. The flow in the divergent portion of the nozzle is supersonic.

D. 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.

What is the correct answer?

4

Water boils when its vapour pressure

A. Equals that of the surroundings

B. Equals 760 mm of mercury

C. Equals to atmospheric pressure

D. Equals the pressure of water in the container

What is the correct answer?

4

The ratio of the isentropic heat drop to the heat supplied, is called

A. Reheat factor

B. Stage efficiency

C. Internal efficiency

D. Rankine efficiency

What is the correct answer?

4

De-Laval turbines are mostly used

A. Where low speeds are required

B. For small power purposes and low speeds

C. For large power purposes

D. For small power purposes and high speeds

What is the correct answer?

4

Ultimate analysis of fuel is determination of percentage of

A. Carbon, hydrogen, nitrogen, sulphur, moisture

B. Fixed carbon, ash, volatile matter, moisture

C. Higher calorific value

D. Lower calorific value

What is the correct answer?

4

In a boiler, the heat is lost

A. To dry flue gases

B. In moisture present in the fuel

C. To steam formed by combustion of hydrogen per kg of fuel

D. All of the above

What is the correct answer?

4

The function of an eccentric rod is

A. To provide reciprocating motion to the slide valve

B. To convert reciprocating motion of the piston into rotary motion of the crank

C. To convert rotary motion of the crankshaft into to and fro motion of the valve rod

D. To provide simple harmonic motion to the D-slide valve

What is the correct answer?

4

The aim of a compound steam engine is

A. To reduce the ratio of expansion in each cylinder

B. To reduce the length of stroke

C. To reduce the temperature range in each cylinder

D. All of the above

What is the correct answer?

4

The critical pressure ratio for gases is

A. 0.528

B. 0.546

C. 0.577

D. 0.582

What is the correct answer?

4

One kilowatt-hour energy is equivalent to

A. 1000 J

B. 360 kJ

C. 3600 kJ

D. 3600 kW/sec

What is the correct answer?

4

In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be

A. 260 kW

B. 282 kW

C. 296 kW

D. 302 kW

What is the correct answer?

4

Lancashire boiler is a

A. Stationary fire tube boiler

B. Stationary water tube boiler

C. Water tube boiler with natural/forced circulation

D. Mobile fire tube boiler