# Compressors, Gas Turbines and Jet Engines MCQ Practice Test – Set 14 :: Mechanical Engineering

Are you guys looking for Mechanical Engineering MCQ Questions with Answers PDF Free Download as per Mechanical Engineering new exam pattern? You came to the right page. This may assist you to understand and check your knowledge about the Subjects. Students also can take a free test of the Multiple Choice Questions of Mechanical Engineering. Each question has four options followed by the right answer. These Mechanical Engineering MCQ Questions are selected supported by the newest exam pattern.

(A) Isothermal
(B) Isentropic
(D) Isochoric

## Q2. Which of the following statement is wrong?

(A) In a two stage reciprocating air compressor with complete intercooling, maximum work is saved
(B) The minimum work required for a two stage reciprocating air compressor is double the work required for each stage
(C) The ratio of the volume of free air delivery per stroke to the swept volume of the piston is called volumetric efficiency
(D) None of the above

## Q3. Efficiency of gas turbine is increased by

(A) Reheating
(B) Inter cooling
(D) All of the above

(A) 10 to 40%
(B) 40 to 60%
(C) 60 to 70%
(D) 70 to 90%

## Q5. In jet engines the products of combustion after passing through the gas turbine are discharged into

(A) Atmosphere
(B) Back to the compressor
(C) Discharge nozzle
(D) Vacuum

## Q6. For speed above 3000 km/hour, it is more advantageous to use

(A) Turbojet engine
(B) Ramjet engine
(C) Propellers
(D) Rockets

## Q7. 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

Answer: (A) Atmospheric conditions at any specific location

## Q8. For slow speed large capacity compressor, following type of valve will be best suited

(A) Poppet valve
(B) Mechanical valve of the Corliss, sleeve, rotary or semi rotary type
(C) Disc or feather type
(D) Any of the above

## Q9. The volumetric efficiency of compressor with increase in compression ratio will

(A) Increase
(B) Decrease
(C) Remain same
(D) May increase or decrease depending on clearance volume

## Q10. Pick up the correct statement

(A) Gas turbine uses low air-fuel ratio to economise on fuel
(B) Gas turbine uses high air-fuel ratio to reduce outgoing temperature
(C) Gas turbine uses low air-fuel ratio to develop the high thrust required
(D) All of the above

Answer: (B) Gas turbine uses high air-fuel ratio to reduce outgoing temperature

## Q11. The fuel consumption in gas turbines is accounted for by

(A) Lower heating value
(B) Higher heating value
(C) Heating value
(D) Higher calorific value

## Q12. Temperature of gases at end of compression as compared to exhaust gases in a gas turbine is

(A) Higher
(B) Lower
(C) Equal
(D) Can’t be compared

## Q13. In the axial flow gas turbine, the work ratio is the ratio of

(A) Compressor work and turbine work
(B) Output and input
(D) Actual compressor work and theoretical compressor work

(A) Same
(B) More
(C) Less
(D) Zero