Mechanical Engineering Mcqs

Diesel engines have low specific fuel consumption compared to petrol engine. This statement is____________________?

(A) not true

(B) true at full load

(C) true at part load

(D) true at both part and full load

(D) there could not be any such criterion

Submitted By: Ali Uppal


In order to prevent knock in the S.I. engines, the charge away from the spark plug should have___________________?

(A) low temperature

(B) low density

(C) long ignition delay

(D) rich mixture

(D) all of the above

Submitted By: Ali Uppal


To reduce the possibility of knock in the C.I. engines, the first elements of fuel and air should have_______________?

(A) high temperature

(B) high density

(C) short delay

(D) reactive mixture

(D) all of the above

Submitted By: Ali Uppal


Piston rings are plated with chromium,cadmium or phosphate in order to__________________?

(A) reduce cost

(B) improve surface finish

(C) prevent clogging

(D) reduce wear and eliminate scuffing

(D) improve heat transfer

Submitted By: Ali Uppal


The pistons are usually given a coating such as tin plating in order to________________?

(A) reduce weight

(B) conduct heat efficiently

(C) reduce possibility of scoring

(D) reduce friction

(D) increase lubrication effect

Submitted By: Ali Uppal


Submitted By: Ali Uppal


The top piston ring nearer to the piston crown is known as_____________________?

(A) compression ring

(B) oil ring

(C) scrapper ring

(D) groove ring

(D) leading ring

Submitted By: Ali Uppal


Piston rings are usually made of___________________?

(A) cast iron

(B) aluminium

(C) phosphor bronze

(D) babbitt

(D) carbon steel

Submitted By: Ali Uppal


The m.e.p. of a diesel cycle having fixed compression ratio with increase in cut-off will_________________?

(A) increase

(B) decreae

(C) be unaffected

(D) depend on other factors

(D) unpredictable

Submitted By: Ali Uppal


Detonation can be controlled by_____________________?

(A) varying compression ratio

(B) using lian mixture

(C) retarding the spark timing

(D) reducing the r.p.m.

(D) increasing inlet pressure

Submitted By: Ali Uppal