Mechanical Engineering Mcqs

Hot air standard diesel cycle efficiency with increase in value of C„_______________?

(A) increases

(B) decreases

(C) remains unaffected

(D) depends on other factors

(D) unpredictable

Submitted By: Ali Uppal


In open combustion chamber in diesel engines____________________?

(A) the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture

(B) fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat

(C) only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge

(D) fuel is injected at atmospheric pres¬sure

(D) there are no valves.

Submitted By: Ali Uppal


In petrol engine using a fixed octane rating fuel and fixed compression ratio, super charging will_________________?

(A) increase the knocking tendency

(B) decrease the knocking tendency

(C) not affect the knocking tendency

(D) increase or decrease knocking tendency depending on strength and time of spark

(D) unpredictable

Submitted By: Ali Uppal


Theoretically, the following engine should have maximum efficiency________________?

(A) gas engine

(B) 2-stroke S.I. engine

(C) 4-stroke S.I. engine

(D) steam engine

(D) 4-stroke C.I. engine

Submitted By: Ali Uppal


Submitted By: Ali Uppal


The ignition coil in diesel engines produces voltage of the order of________________?

(A) 6 to 12 volts

(B) 240 volts

(C) 1000 volts

(D) 20,000 volts

(D) 80,000 volts

Submitted By: Ali Uppal


In precombustion chamber in diesel engine________________?

(A) The shape and layout of the pistion crown, the inlet port, and the valve produce the turbulent effect of fuel mixture

(B) Fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat

(C) Only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge

(D) There are no valves

Submitted By: Ali Uppal


In a diesel engine, injection pressure developed by injector is of the order of______________?

(A) 10 kg/cm2

(B) 100 kg/cm2

(C) 500 kg/cm2

(D) 1400 kg/cm2

Submitted By: Ali Uppal


In the case of petrol engine at maximum output, the percentage of CO in exhaust gases is ____________________?

(A) Zero

(B) 5-10%

(C) Depends on load and quality of fuel

(D) Considerable percent

Submitted By: Ali Uppal


Submitted By: Ali Uppal