Mechanical Engineering Mcqs

In a diesel engine, the fuel is ignited by___________________?

(A) spark

(B) injected fuel

(C) heat resulting from compressing air that is supplied for combustion

(D) ignition

(D) combustion chamber

Submitted By: Ali Uppal


The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is__________________?

(A) same

(B) less

(C) more

(D) more or less depending on power rating

(D) unpredictable

Submitted By: Ali Uppal


Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged ?

(A) yes

(B) no

(C) to some extent

(D) unpredictable

(D) depends on other factors

Submitted By: Ali Uppal


Scavenging air in diesel engine means___________________?

(A) air used for combustion sent under pres-sure

(B) forced air for cooling cylinder

(C) burnt air containing products of combustion

(D) air used for forcing burnt gases out of engine’s cylinder during the exhaust period

(D) air fuel mixture

Submitted By: Ali Uppal


Submitted By: Ali Uppal


The knock in diesel engine occurs due to____________________?

(A) instantaneous and rapid burning of the first part of the charge

(B) instantaneous atuo iginition of last part of charge

(C) delayed burning of the first part of the charge

(D) reduction of delay period

(D) all ot the above

Submitted By: Ali Uppal


The output of a diesel engine can be increased without increasing the engine revolution or size in following way_________________?

(A) feeding more fuel

(B) increasing flywheel size

(C) heating incoming air

(D) scavenging

(D) supercharging

Submitted By: Ali Uppal


Which of the following is not an interns combustion engine___________________?

(A) 2-stroke petrol engine

(B) 4-stroke petrol engine

(C) diesel engine

(D) gas turbine

(D) steam turbine

Submitted By: Ali Uppal


The air requirement of a petrol engine during starting compared to theoretical airequired for complete combustion is___________________?

(A) more

(B) loss

(C) same

(D) may be more or less depending on engine capacity

(D) unpredictable

Submitted By: Ali Uppal


Submitted By: Ali Uppal