Internal Combustion Engine Questions and Answers Part-15

1. Which of the following statement is not correct with respect to alcohols as alternate fuel in IC engines?
a) anti-knock characteristics of alcohol is poor
b) alcohol contains about half the heat energy of gasoline/litre
c) alcohol does not vaporize as easily as gasoline
d) alcohols are corrosive in nature

Answer: a
Explanation: Anti-knock characteristics of alcohol is good.

2. What is the mixture of Gasohol?
a) 90% ethanol + 10% gasoline
b) 10% ethanol + 90% gasoline
c) 40% ethanol + 60% gasoline
d) 50% ethanol + 50% gasoline

Answer: b
Explanation: 10% ethanol + 90% gasoline makes gashol.

3. Stoichiometric air-fuel ratio of alcohol when compared to gasoline is?
a) higher
b) lower
c) equal
d) none of the mentioned

Answer: b
Explanation: lower

4. Small amount of gasoline is added to alcohol to ___________
a) reduce the emission
b) to increase the power output
c) to increase the efficiency
d) to improve cold weather starting

Answer: d
Explanation: to improve cold weather starting

5. Methanol by itself is not a good CI engine fuel because ___________
a) its octane number is high
b) its cetane number is low
c) all of the mentioned
d) none of the mentioned

Answer: c
Explanation: all of the mentioned

6. Anti-knock characteristics of alcohol when compared to gasoline is?
a) higher
b) lower
c) equal
d) none of the mentioned

Answer: a
Explanation: Anti-knock characteristics of alcohol when compared to gasoline is higher and stoichiometric air-fuel ratio of alcohol when compared to gasoline is generally lower.

7. Alcohols alone cannot be used in CI engines as ___________
a) their self ignition temperature is high
b) latent heat of vaporization is high
c) all of the mentioned
d) none of the mentioned

Answer: c
Explanation: all of the mentioned

8. The compression ratio of alcohol fuel lies between ___________
a) 11:1 to 13:1
b) 7:1 to 9:1
c) 5:1 to 7:1
d) none of the mentioned

Answer: a
Explanation: The compression ratio of alcohol fuel lies between 11:1 to 13:1

9. The calorific value of alcohols is _____________ in diesel oil.
a) higher than
b) lower than
c) same
d) none of the mentioned

Answer: b
Explanation: lower than

10. Which is the effective inhibitor of pre-ignition?
a) alcohol
b) water
c) lead
d) none of the mentioned

Answer: b
Explanation: water