Mechanical Engineering Mcqs

What will be the volume of air at 327°C if its volume at 27°C is 1.5 m3/mt ?

(A) 3 m3/mt

(B) 1.5 m3/mt

(C) 18 m3/mt

(D) 6 m3/mt

(D) 0.75 m3/mt

Submitted By: Ali Uppal


Isothermal compression though most efficient, but is not -practicable because_________________?

(A) ityrequires very big cylinder

(B) it does not increase pressure much

(C) it is impossible in practice

(D) compressor has to run at very slow speed to achieve it

(D) it requires cylinder to be placed in water

Submitted By: Ali Uppal


Inter cooling in compressors__________________?

(A) cools the delivered air

(B) results in saving of power in compressing a given volume to given pressure

(C) is the standard practice for big compressors

(D) enables compression in two stages

(D) prevents compressor jacket running very hot

Submitted By: Ali Uppal


The compressor capacity with decrease in suction temperature_________________?

(A) increases

(B) decreases

(C) remains unaffected

(D) may increase or decrease depending on compressor capacity

(D) increases upto certain limit and then decreases

Submitted By: Ali Uppal


Standard air is the air at_____________________?

(A) atmospheric conditions at any specific location

(B) 20°C and 1 kg/cm2 and relative humidity 36%

(C) 0°C and standard atmospheric conditions

(D) 15°C and 1 kg/cm2

(D) 25°C, 1 kg/cm2 and RH of 60%.

Submitted By: Ali Uppal


Maximum work is done in compressing air when the compression is_________________?

(A) isothermal

(B) adiabatic

(C) polytropic

(D) any one of the above

(D) none of the above

Submitted By: Ali Uppal


The capacity of a compressor is 5 m /mih. 5 m /min refers to_______________?

(A) standard air

(B) free air

(C) compressed air

(D) compressed air at delivery pressure

(D) air sucked

Submitted By: Ali Uppal


Free air is the air at________________?

(A) atmospheric conditions at any specific location

(B) 20°C and 1 kg/cm2 and relative humidity of 36%

(C) 0°C and standard atmospheric conditions

(D) 15°C and 1 kg/cm2

(D) 25°C, 1 kg/cm2 and relative humidity of 50%.

Submitted By: Ali Uppal


1 m of air at atmospheric condition weighs approximately__________________?

(A) 0.5 kg

(B) 1.0 kg

(C) 1.3 kg

(D) 2.2 kg

(D) 3.2 kg

Submitted By: Ali Uppal


Ratio of compression is the ratio of__________________?

(A) gauge discharge pressure to the gauge intake pressure

(B) absolute discharge pressure to the ab-solute intake pressure

(C) pressures at discharge and suction cor-responding to same temperature

(D) stroke volume and clearance volume

(D) none of the above

Submitted By: Ali Uppal