225. Detonation in petrol engines can be suppressed or reduced by the addition of small quantity of
A.Lead ethide
B.Iso-octane
C.N-heptane
D.Methyl napthalene
226. It is possible to obtain a number of blends of the fuel by mixing/blending
A.Cetane with iso-octane
B.Cetane with α-methyl napthalene
C.Cetane with aldehydes and ketones
D.Cetane with tetra-ethyle lead
227. Compression ratio for spark ignition engines usually varies between
A.4-6
B.6-13
C.10-18
D.14-25
228. Four-stroke petrol engines as compared to two stroke petrol engines having same output rating and same compression ratio have
A.Higher thermal efficiency
B.Lower thermal efficiency
C.Higher specific fuel consumption
D.Higher specific output
229. Compression ratio for compression ignition engines usually varies between
A.4-6
B.6-12
C.10-18
D.14-25
230. The air requirement of a petrol engine during acceleration period in comparison to theoretically correct air required for complete combustion is
A.Less
B.More
C.Same
D.May be less or more depending upon engine capcity
231. Cetane number of petrol is around
A.10
B.15-20
C.35
D.45-55
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