Thermodynamics 6

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject:  Thermodynamics 6

Part 6: List for questions and answers of Thermodynamics

Q1. One tonne of refrigeration is approximately equal to
a) 3.5 kj / min
b) 3.5 W
c) 211 kw
d) 211 kj / min

Q2. A coal containing very high percentage of durain is called __________ coal
a) Bright
b) Splint
c) Non-banded
d) Boghead

Q3. During combustion of gaseous fuels, deficiency of air
a) Lengthens the flame
b) Tends to shorten the flame
c) Does not affect the flame length
d) Increases the flame temperature

Q4. Gross and net calorific value of a fuel will be the same
a) If its ash content is zero
b) Ifits carbon content is very low
c) If its hydrogen/hydrogen compound content is zero
d) Under no circumstances

Q5. Low temperature carbonisation
a) Is mainly for producing the smokeless domestic coke
b) Us meant for the production of ‘metallurgical coke’
c) Produces higher quantity of gas than high temperature carbonisation
d) Produces less quantity of tar than high temperature carbonisation

Q6. Which of the following is not used as a binder in coal briquetting ?
a) Tar
b) Molasses
c) Pitch
d) Line

Q7. Size of blast furnace grade coke is __________ mm
a) 25-80
b) 0-15
c) 15-25
d) Is greater than 100

Q8. Presence of __________ in a dry gaseous fuel does not contribute to its calorific value
a) Sulphur
b) Oxygen
c) Hydrogen
d) Carbon

Q9. The internal energy of the combustion products is __________ compared to that of reactants
a) More
b) Less
c) Equal
d) More or less; (depends on the state of fuel.)

Q10. Which of the following is not a product of tar distillation?
a) Phenol & naphthalene
b) Benzol & pitch
c) Anthracene & creosote
d) None of these

Q11. Junker’s calorimeter is used to determine the calorific value of
a) Pulverised coal
b) Gaseous fuels
c) Fuel oil
d) None of these

Q12. Combustion reaction of fuels is a/an __________ reaction
a) Auto catalytic
b) Exothermic
c) Endothermic
d) None of these

Q13. Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its
a) Caking index
b) Yield of carbonised products
c) Friability & oxygen content
d) Calorific value

Q14. Which of the following constituents of coal is the most important in the production of coke?
a) Moisture
b) Ash
c) Volatiles
d) Carbon

Q15. Pick out the wrong statement
a) LPG is also used as fuel for automobiles & small furnaces and for cutting & welding of metals
b) The minimum temperature, at which a petroleum oil vapour catches fire and
continues to burn, is called its flash point
c) Each ton of petroleum oil on distillation produces about 30-50 Nm3 of gas
d) Maximum yield of naphthalene is obtained on distillation of crude oil

Q16. Stack heat losses can be minimised by
a) Controlling the excess air
b) Oxygen enrichment of combustion air
c) Using low c.v. Fuels
d) Maintaining proper draft in the furnace

Q17. Laboratory gas is obtained by the cracking of
a) Gasoline
b) Diesel
c) Fuel oil
d) Kerosene

Q18. Bituminous coal
a) Ignites less easily than anthrcite
b) Is generally coking
c) Iurns with smoky yellow flame
d) Both (b) and (c)

Q19. Ratio of primary air to secondary air increases with increase in the rank of coal, because the
a) High rank coals have higher amount of volatile matter
b) Ratio of fixed carbon to volatile matter increases
c) Oxygen content progressively decreases
d) Calorific value of the coal increases

Q20. A coal having high amount of volatile matter
a) Would require smaller combustion chamber
b) Produces very little of tar and gas on carbonisation
c) Ignites easily and burns with long smoky flame
d) All (a), (b) and (c)

Part 6: List for questions and answers of Thermodynamics

Q1. Answer: d

Q2. Answer: b

Q3. Answer: a

Q4. Answer: c

Q5. Answer: a

Q6. Answer: d

Q7. Answer: a

Q8. Answer: a

Q9. Answer: b

Q10. Answer: d

Q11. Answer: b

Q12. Answer: b

Q13. Answer: c

Q14. Answer: d

Q15. Answer: b

Q16. Answer: a

Q17. Answer: d

Q18. Answer: d

Q19. Answer: b

Q20. Answer: d