# Compressors, Gas Turbines and Jet Engines MCQ Practice Test – Set 15 :: 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.

## Q1. The volume of air delivered by the compressor is called

(A) Free air delivery
(B) Compressor capacity
(C) Swept volume
(D) None of these

## Q2. The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the

(A) Adiabatic temperature drop in the stage
(B) Total temperature drop
(C) Total temperature drop in the stage

Answer: (C) Total temperature drop in the stage

## Q3. The weight per horse power ratio for gas in Turbine as compared to I.C. engine and steam turbine is

(A) Same
(B) Higher
(C) Lower
(D) None of these

## Q4. Which of the following plants is smallest and lightest for generating a given amount of power?

(A) Gas turbine plant
(B) Petrol engine
(C) Diesel engine
(D) Solar plant

## Q5. 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

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

## Q6. During base load operation, the best method of controlling compressor is

(A) Start-stop motor
(C) Relief valve
(D) Variable speed

## Q7. Stalling of blades in axial flow compressor is the phenomenon of

(A) Air stream blocking the passage
(B) Motion of air at sonic velocity
(C) Unsteady periodic and reversed flow

(A) Vi = Vo
(B) Vt > Vo
(C) U < Vo
(D) V = Uo

## Q9. The propulsive power of the rocket is (where v₁ = Jet velocity, and v₂ = Aircraft velocity)

(A) (v₁² -v₂²)/2g
(B) (v₁ – v₂)²/2g
(C) (v₁² -v₂²)/g
(D) (v₁ – v₂)²/g

## Q10. Inter-cooling in gas turbine results in

(A) Increase in net output but decrease in thermal efficiency
(B) Increase in thermal efficiency but decrease in net output
(C) Increase in both thermal efficiency and net output
(D) Decrease in both thermal efficiency and net output

Answer:(A) Increase in net output but decrease in thermal efficiency

## Q11. The degree of reaction in an axial flow compressor is defined as the ratio of static enthalpy rise in the

(A) Rotor to static enthalpy rise in the stator
(B) Stator to static enthalpy rise in the rotor
(C) Rotor to static enthalpy rise in the stage
(D) Stator to static enthalpy rise in the stage

Answer:(C) Rotor to static enthalpy rise in the stage

## Q12. In a single stage, single acting reciprocating air compressor, without clearance, the work-done on the air during isentropic compression is __ the heat required to raise the temperature of air from T₁ to T₂ at a constant pressure.

(A) Equal to
(B) Less than
(C) Greater than
(D) None of these

## Q13. The type of rotary compressor used in gas turbines, is of

(A) Centrifugal type
(B) Axial flow type
(D) None of these