The compression ratio of motor cars is___________________?
A. 5
B. 7
C. 10
D. 13
E. 16
Month: January 2019
Ignition quality of diesel-fuel oil is expressed by an index called__________________?
Ignition quality of diesel-fuel oil is expressed by an index called__________________?
A. octane number
B. cetane number
C. calorific value
D. carbon content
E. ignition temperature
The ignition of charge by some hot surface in the engine cylinder before operation of spark plug is known as________________?
The ignition of charge by some hot surface in the engine cylinder before operation of spark plug is known as________________?
A. auto ignition
B. preignition
C. retarded ignition
D. accelerated ignition
E. detonation
According to Recardo’s theory, detonation occurs due to______________________?
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
E. none of the above
The knocking in diesel engines for given fuel, will be__________________?
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
E. dependent on other factors
Injection lag is_________________?
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
E. none of the above
Carbon residue in diesel oil should not be more than___________________?
Carbon residue in diesel oil should not be more than___________________?
A. 1%
B. 0.5%
C. 0.1%
D. 0.01%
E. 0.001%
Diesel engines have low specific fuel consumption compared to petrol engine. This statement is____________________?
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
E. there could not be any such criterion
In order to prevent knock in the S.I. engines, the charge away from the spark plug should have___________________?
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
E. all of the above
To reduce the possibility of knock in the C.I. engines, the first elements of fuel and air should have_______________?
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
E. all of the above