Mechanical Engineering MCQs

A. 30 – 65°c
B. 65 – 220°c
C. 220-350°c
D. 350-450°c

A. Minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
B. Temperature at which it solidifies or congeals
C. That at which it catches fire without external aid
D. Indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off

A. 150°c
B. 240°c
C. 370°c
D. 450°c

A. Iso-octane
B. Mixture of normal heptane and iso-oc-tane
C. Alpha methyl napthalene
D. Mixture of methane and ethane

A. To increase the octane rating of the fuel
B. To increase the cetane rating of the fuel
C. As a defrosting agent
D. As a superior type of fluid compared to others

A. Accelerates auto-ignition
B. Helps to resist auto-ignition
C. Does not affect auto-ignition
D. Has no relation with auto-ighition

A. Lean mixture has high reaction time
B. Rich mixture has high reaction time
C. Chemically correct mixture has mini-mum reaction time
D. All of the above

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 plunger starts to pump fuel
C. Time corresponding to actual injection and top dead center
D. Time corresopnding to actual ingition and top dead center

A. Cetane
B. Mixture of cetane and alphamethyl napthalene
C. Ethylene dibromide
D. Mixture of aldehydes and ketones

A. Heavy turbulence
B. Improved scavenging
C. Heavy supercharging
D. Detonation