Mechanical Engineering Mcqs

The function of a fuel pump in a petrol pump is to______________________?

(A) inject fuel in cylinder

(B) supply fuel when carburettor fails

(C) pump fuel so that it reaches carburettor (to improve thermal efficiency)

(D) does not exist

Submitted By: Ali Uppal


Submitted By: Ali Uppal


The spark plug gap is normally maintained at________________?

(A) 0.1 to 0.2 mm

(B) 0.2 to 0.4 mm

(C) 0.45 to 0.6 mm

(D) 0.6 to 0.8 mm

(D) 0.8 to 1 mm

Submitted By: Ali Uppal


The delay period in petrol engine is of the order of__________________?

(A) 0.001 sec

(B) 0.002 see

(C) 0.01 sec

(D) 0.05 sec

(D) 0.1 sec

Submitted By: Ali Uppal


Auto-ignition temperature is____________________?

(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

(D) indicated by 50% distillation temperature

Submitted By: Ali Uppal


Petrol is distilled at a temperature in range of__________________?

(A) 30 – 65°C

(B) 65 – 220°C

(C) 220-350°C

(D) 350-450°C

(D) 450-550°C

Submitted By: Ali Uppal


Self-ignition temperature of petrol is of the order of___________________?

(A) 150°C

(B) 240°C

(C) 370°C

(D) 450°C

(D) more than 500°C.

Submitted By: Ali Uppal


Octane number is determined by comparing the performance of the petrol with the following hydrocarbons__________________?

(A) iso-octane

(B) mixture of normal heptane and iso-oc-tane

(C) alpha methyl napthalene

(D) mixture of methane and ethane

(D) mixture of paraffins and aromatics

Submitted By: Ali Uppal


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

(D) none of the above

Submitted By: Ali Uppal


Carbon residue in diesel oil should not be more than___________________?

(A) 1%

(B) 0.5%

(C) 0.1%

(D) 0.01%

(D) 0.001%

Submitted By: Ali Uppal