Thermal Engineering 38

COEP
Lets Crack Online Exam

Objective Questions and Answer: Thermal Engineering 38

Subject: Thermal Engineering 38

Part 38: Objective questions and answers of Thermal Engineering

 

Q1. Primary 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 C02 at higher zone

d) Air delivered by forced draft fan

 

Q2. 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

 

Q3. Presence of moisture in fuel oil would

a) Keep the burner tips cool

b) Aid in proper combustion

c) Cause sputtering, possibly extinguishing flame

d) Clean the nozzles

 

Q4. Gusset stays in a boiler are provided to

a) Prevent the bulging of flat surfaces

b) Avoid explosion in furnace

c) Prevent leakage of hot flue gases

d) Support furnace freely from top

 

Q5. 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

 

Q6. Pour point of fuel oil is the

a) Lowest temperature at which oil will flow under set condition

b) Storage temperature

c) Temperature at which fuel is pumped through burners

d) Temperature at which oil is transported

 

Q7. Secondary air is the 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 C02 at higher zone

d) Air delivered by induced draft fan

 

Q8. The behavior 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

 

Q9. Pick up wrong statement about desired properties of a good fuel

a) High calorific value

b) Produce minimum smoke and gases

c) Ease in storing

d) High ignition point

 

Q10. Sulphur in coal results in

a) Causing clinkering and slagging

b) Corroding air heaters

c) Spontaneous combustion during coal storage

d) All of the above.

 

Q11. Caking coals are those which

a) Form lumps or masses of coke

b) Burn freely

c) Show little or no fusing action

d) Burn completely

 

Q12. Green coal, in order to be burnt, must be

a) Heated sufficiently

b) Burnt in excess air

c) Heated to its ignition point

d) Burnt as powder

 

Q13. The ultimate analysis of fuel lists

a) Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume

b) Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight

c) Fuel constituents as percent by volume of moisture, volatile, fixed carbon and ash

d) Fuel constituents as percent by weight of moisture, volatile, fixed carbon and ash

 

Q14. The proximate analysis of fuel lists

a) Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume

b) Various chemical constituents, carbon, hydrogen, oxygen, etc. Plus ash as per-cents by weight

c) Fuel constituents as percent by volume of moisture, volatile, fixed carbon and ash

d) Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash

 

Q15. Tertiary air is the air used to

a) Provide air around burners for obtaining optimum combustion

b) Transport and dry the coal

c) Cool the scanners

d) Convert CO (formed in lower zone of furnace) into C02 at higher zone.

 

Q16. The safety valve on boiler drum compared to safety valve on superheater is set at

a) Same value

b) Higher value

c) Lower value

d) Lower/higher depending on steam flow

 

Q17. Which is not correct statement about pulverised fuel firing?

a) High burning rate is possible

b) Heat release can be easily controlled

c) Fuel burns economically

d) It is the best technique for burning high ash content fuel having low fusion ash

 

Q18. The three 'Ts' for good combustion are

a) Temperature, time, and turbulence

b) Total air, true fuel, and turbulence

c) Thorough mixing, total air, and temperature

d) Total air, time, and temperature

 

Q19. Which is not correct statement about the function of furnace?

a) To provide proper conditions for continuous complete combustion

b) Mix fuel with air and ignite

c) Separate ash from coal

d) Maintain heat supply to prepare and ignite the incoming fuel

 

Q20. Which is not correct statement about effect of sulphur in fuel?

a) It has heating value

b) It helps in electrostatic precipitation of ash in flue-gases

c) It leads to corrosion of air heaters, ducting, etc. If flue gas exit temperature is low

d) It erodes furnace walls

 

Part 38: Objective questions and answers of Thermal Engineering

 

Q1. Answer: b

Q2. Answer: d

Q3. Answer: c

Q4. Answer: a

Q5. Answer: a

Q6. Answer: a

Q7. Answer: a

Q8. Answer: c

Q9. Answer: d

Q10. Answer: d

Q11. Answer: a

Q12. Answer: c

Q13. Answer: b

Q14. Answer: d

Q15. Answer: d

Q16. Answer: b

Q17. Answer: d

Q18. Answer: a

Q19. Answer: c

Q20. Answer: d

Be the first to comment

Leave a Reply