250+ TOP MCQs on Dual Fuel Operations and Answers

IC Engines Multiple Choice Questions on “Dual Fuel Operations”.

1. The normal heptane(C₇H₁₆) is given a rating of ____________ octane number.
a) 0
b) 50
c) 100
d) 120
Answer: a
Clarification: None.

2. A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of ___________
a) 75% iso-octane and 25% normal heptane
b) 75% normal heptane and 25% iso-octane
c) 75% petrol and 25% diesel
d) 75% diesel and 25% petrol
Answer: a
Clarification: None.

3. What are the two reference fuels used for cetane rating?
a) cetane and iso-octane
b) cetane and alpha-methyl naphthalene
c) cetane and normal heptane
d) none of the mentioned
Answer: b
Clarification: Cetane and alpha-methyl naphthalene are the reference fuels taken for cetane rating.

4. A mixture containing 65% of iso-octane and 35% of normal heptane will have ___________
a) cetane number 65
b) octane number 65
c) cetane number 35
d) octane number 35
Answer: b
Clarification: A mixture containing 65% of iso-octane and 35% of normal heptane will have octane number 65 as octane number is the number percentage containing iso-octane.

5. A fuel of cetane number 40 has the same ignition quality as a mixture of ___________
a) 40% cetane and 60% alpha methyl naphthalene
b) 40% alpha methyl naphthalene and 60% cetane
c) 40% petrol and 60% diesel
d) 40% diesel and 60% petrol
Answer: a
Clarification: A fuel of cetane number 40 has the same ignition quality as a mixture of 40% cetane and 60% alpha methyl naphthalene as cetane number is counted on cetane percentage.

6. Which of the following is the anti-knock for compression ignition engines?
a) naphthene
b) tetra ethyl lead
c) amyl nitrate
d) hexadecane
Answer: c
Clarification: Amyl nitrate is the anti-knock for compression ignition engines.

7. The fuels in order of decreasing knock tendency for spark ignition engines are ___________
a) paraffins, aromatics, naphthenes
b) paraffins, naphthenes, aromatics
c) naphthenes, aromatics, paraffins
d) none of the mentioned
Answer: b
Clarification: Paraffins have the highest knocking tendency, while naphthenes have less knocking than paraffins and aromatics have the lowest knocking tendency.

8. Which of the following fuel has little tendency towards detonation?
a) Benzene
b) Iso-octane
c) Normal heptane
d) Alcohol
Answer: b
Clarification: Benzene has little tendency towards detonation.

9. Which of the following fuel detonates readily?
a) Benzene
b) Iso-octane
c) Normal heptane
d) Alcohol
Answer: c
Clarification: Normal heptane detonates readily.

10. The knocking tendency in spark ignition engines can be decreased by adding dopes like tetra ethyl lead and ethylene dibromide.
a) True
b) False
Answer: a
Clarification: None.