31. The thermal efficiency of petrol and gas engines is about
15%
30%
50%
70%
✅ The correct answer is option B.
IC Engines and Nuclear Power Plants MCQs
32. Alpha-methyl-naphthalene (C11 H10) has a cetane number of
0
50
100
120
✅ The correct answer is option A.
33. The air-fuel ratio of the petrol engine is controlled by
carburettor
injector
governor
none of these
✅ The correct answer is option A.
34. The thermodynamic cycle on which the petrol engine works, is
Otto cycle
Joule cycle
Rankine cycle
Stirling cycle
✅ The correct answer is option A.
35. The pressure at the end of compression, in petrol engines, is approximately
10 bar
20 bar
25 bar
35 bar
✅ The correct answer is option A.
36. In a two stroke engine, the working cycle is completed in two revolutions of the crankshaft.
Correct
Incorrect
✅ The correct answer is option B.
37. A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of
75% iso-octane and 25% normal heptane
75% normal heptane and 25% iso-octane
75% petrol and 25% diesel
75% diesel and 25% pet
✅ The correct answer is option A.
38. Enriched uranium may contain fissionable contents from
1 to 40%
10 to 50%
1 to 80%
1 to 99%
✅ The correct answer is option D.
39. Lubrication in I.C. engines dissipates the heat generated from the moving parts due to friction.
TRUE
FALSE
✅ The correct answer is option A.
40. In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as
scavenging
detonation
supercharging
polymerisation
✅ The correct answer is option A.