A. No possibility of obtaining complete combustion at high temperature
B. Always loss of heat from the flame
C. Both A. and B.
D. Neither A. nor B.
Correct Answer: C. Both A. and B. ✔
Last Updated: March 08, 2019
Related MCQs
- Fuel for a fast breeder nuclear reactor is__________?
- C.V. (kcal/Nm3) of gaseous fuels __________ with increase in molecular weight?
- Volatile matter content of metallurgical coke may be around __________ percent?
- Coking coals are invariably__________?
- Ratio of primary air to secondary air increases with increase in the rank of coal, because the__________?
- Oxygen required for theoretically complete combustion of 1 Nm3 methane is __________ Nm3?
- Calorific value of wood gas is about __________ kcal/Nm3?
- The maximum adiabatic flame temperature in air as compared to that in pure oxygen is__________?
- Ammonia content in raw coke oven gas is about __________ gm/Nm3?
- Presence of __________ in a dry gaseous fuel does not contribute to its calorific value?
- For maximum discharge through a chimney, its height should be__________?
- Which of the following has the highest flame speed ?
- Which of the following fuels is generally not used in thermal power plant boiler firing ?
- Use of excess of combustion air in the combustion of fuels results in__________?
- Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the__________?
- Which of the following is called “blue gas”?
- Rate of low temperature oxidation of coal due to bad storage conditions__________?
- Dust content in raw blast furnace gas is about __________ gm/Nm3; hence it is cleaned to the dust level of about < 10 mg /Nm3 before use?
- When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the __________ of coal?
- Flue gas discharge velocity through chimney of a big thermal power plant may be around __________ m/sec?
- Bomb calorimeter is used for the determination of calorific value of the __________ fuels?
- Coke ovens in steel plant are heated by __________?
- Soft coke is not __________?
- Percentage of hydrogen in coke oven gas may be around __________?
- A coal with high ash content is undesirable, as__________?
- Which of the following is the most poisonous gas ?
- Gross heating value of coal is __________ the net heating value?
- Which of the following accentuates clinkering trouble on furnace grate burning coal ?
- Increase in ash content of blast furnace coke__________?
- The difference between total carbon and fixed carbon of coal will be minimum in case of__________?
- In high temperature carbonisation (as compared to low temperature carbonisation) of coal__________?
- Gross heating value of coal is __________ the net heating value?
- The internal energy of the combustion products is __________ compared to that of reactants?
- Lignite is __________?
- High pressure coal gasification is employed in __________ process?
- Use of pulverised coal in boiler furnace provides__________?
- Which of the following fuel gases is heavier than air ?
- Which of the following is not a by-product fuel ?
- Cannel coal__________?
- In Lurgi coal gasifier__________?
- Which of the following has the highest flame velocity ?
- Which of the following has the highest theoretical flame temperature ?
- Which of the following will generate maximum volume of product of complete combustion (Nm3/Nm3 of fuel) ?
- Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing ?
- C/H ratio is the minimum in case of__________?
- The calorific value of a gas of composition CO2 = 20%, H2 = 50%, CH4 = 30%, is y. If the composition of gas is changed to H2 = 50%, CH4 = 30%, CO2 = 10%, N2 = 10%, then the calorific value will be__________?
- The gasification reaction represented by, C + H2O = CO + H2, is__________?
- Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm3?
- For long flame and easy ignition, the coal used should have__________?
- Coke oven gas is stripped of its H2S and mercaptans content by__________?
- Presence of nitrogen in combustion air does not reduce the __________?