Ignition quality of diesel-fuel oil is expressed by an index called__________________?

A. Octane number
B. Cetane number
C. Calorific value
D. Carbon content

According to Recardo’s theory, detonation occurs due to______________________?

A. Instantaneous auto-ignition of last part of charge to be burnt
B. Improper mixing of air and fuel
C. Improper combustion
D. Self ignition temperature has nothing to do with detonation

Injection lag is_________________?

A. The time taken by fuel after injection (before top dead center) to reach upto auto-ignition temperature
B. Time before actual fuel injection and the pump pluger starts to pump fuel
C. Time corresponding to actual injection and top dead center
D. Time corresponding to actual ignition and top dead center

The knocking in diesel engines for given fuel, will be__________________?

A. Enhanced by increasing compression ratio
B. Enhanced by decreasing compression ratio
C. Unaflected by compression ratio
D. First enhanced by increasig compression ratio upto a limit beyond which it will be suppressed

Carbon residue in diesel oil should not be more than___________________?

A. 1%
B. 0.5%
C. 0.1%
D. 0.01%

Diesel engines have low specific fuel consumption compared to petrol engine. This statement is____________________?

A. Not true
B. True at full load
C. True at part load
D. True at both part and full load

To reduce the possibility of knock in the C.I. engines, the first elements of fuel and air should have_______________?

A. high temperature
B. high density
C. short delay
D. reactive mixture

In order to prevent knock in the S.I. engines, the charge away from the spark plug should have___________________?

A. low temperature
B. low density
C. long ignition delay
D. rich mixture

The pistons are usually given a coating such as tin plating in order to________________?

A. Reduce weight
B. Conduct heat efficiently
C. Reduce possibility of scoring
D. Reduce friction

Piston rings are plated with chromium,cadmium or phosphate in order to__________________?

A. Reduce cost
B. Improve surface finish
C. Prevent clogging
D. Reduce wear and eliminate scuffing