Mechanical Engineering MCQs

A. Auto ignition
B. Preignition
C. Retarded ignition
D. Accelerated ignition

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

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

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

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

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

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

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

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

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