Mechanical Engineering Mcqs

The compressor efficiecny is the__________________?

(A) isothermal H.P/indicated H.R

(B) isothermal H.P./shaft H.R

(C) total output/air input

(D) compression work/motor input

(D) none Of the above

Submitted By: Ali Uppal


For a compressor, least work will be done if the compression is________________ ?

(A) isentropic

(B) isothermal

(C) polytropic

(D) somewhere in between isentropic and isothermal

(D) none of the above

Submitted By: Ali Uppal


To avoid moisture troubles, the branch connections from compressed air lines should be taken from_________________?

(A) top side of main

(B) bottom side of main

(C) left side of main

(D) right side of main

(D) any location

Submitted By: Ali Uppal


To aviod moisture troubles, the compressed air main line should __________________?

(A) rise gradually towards the point of use

(B) drop gradually towards the point of use

(C) be laid vertically

(D) be laid exactly horizontally

(D) none of the above

Submitted By: Ali Uppal


The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is_____________________?

(A) less

(B) more

(C) same

(D) more/less depending on compressor capacity

(D) unpredictable

Submitted By: Ali Uppal


The thrust on the rotor in a centrifugal compressor is produced by________________?

(A) radial component

(B) axial component

(C) tangential component

(D) resultant component

Submitted By: Ali Uppal


A compressor at high altitude will draw________________?

(A) more power

(B) less power

(C) same power

(D) more/less power depending on other factors

(D) none of the above

Submitted By: Ali Uppal


A centrifugal compressor works on the principle of__________________?

(A) conversion of pressure energy into kinetic energy

(B) conversion of kinetic energy into pres¬sure energy

(C) centripetal action

(D) generating pressure directly

(D) combination of

Submitted By: Ali Uppal


Submitted By: Ali Uppal


Diffuser in a compressor is used to _____________________?

(A) increase velocity

(B) make the flow stream-line

(C) convert pressure energy into kinetic energy

(D) convert kinetic energy into pressure energy

(D) increase degree of reaction

Submitted By: Ali Uppal