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# 300 Important Compressors, Gas Turbines And Jet Engines MCQ Question and Answer | PDF Free Download

### 1.In a jet propulsion

• AThe propulsive matter is ejected from within the propelled body
• BThe propulsive matter is caused to flow around the propelled body
• CIts functioning does not depend upon presence of air
• DNone of the above

The propulsive matter is caused to flow around the propelled body

Explanation:

• A200°C
• B500°C
• C700°C
• D1000°C

700°C

Explanation:

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

• AHigher
• BLower
• CEqual
• DCan't be compared

Lower

Explanation:

### 4.The hottest point in a gas turbine is

• Aat the base
• Bat the tip
• Cin the center
• Dbetween ~ to i of the blade height

between ~ to i of the blade height

Explanation:

### 5.The compression ratio for the compressor is always _________ unity.

• AEqual to
• BLess than
• CMore than
• DNone of these

More than

Explanation:

### 6.The ideal efficiency of simple gas turbine cycle depends on

• APressure ratio
• BMaximum cycle temperature
• CMinimum cycle temperature
• DAll of the above

Pressure ratio

Explanation:

### 7.There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would

• ARemain same
• BDecrease
• CIncrease
• DNone of the above

Increase

Explanation:

### 8.Ratio of indicated h.p. to shaft h.p. in known as

• ACompressor efficiency
• BIsothermal efficiency
• CVolumetric efficiency
• DMechanical efficiency

Mechanical efficiency

Explanation:

### 9.Ratio of indicated H.P. and brake H.P. is known as

• AMechanical efficiency
• BVolumetric efficiency
• CIsothermal efficiency

Mechanical efficiency

Explanation:

• A6000 KW
• B15 KW
• C600 KW
• D150 KW

15 KW

Explanation:

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

• ALower heating value
• BHigher heating value
• CHeating value
• DHigher calorific value

Lower heating value

Explanation:

### 12.The indicated work per unit mass of air delivered is

• ADirectly proportional to clearance volume
• BGreatly affected by clearance volume
• CNot affected by clearance volume
• DInversely proportional to clearance volume

Not affected by clearance volume

Explanation:

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

• AGas turbine plant
• BPetrol engine
• CDiesel engine
• DSolar plant

Gas turbine plant

Explanation:

### 14.In jet engines, for the efficient production of large power, fuel is burnt in an atmosphere of

• AVacuum
• BAtmospheric air
• CCompressed air
• DOxygen alone

Compressed air

Explanation:

### 15.Gas turbine blades are given a rake

• AEqual to zero
• BIn the direction of motion of blades
• COpposite to the direction of motion of blades
• DDepending on the velocity

In the direction of motion of blades

Explanation:

### 16.Reheating in a gas turbine

• AIncreases the thermal efficiency
• BIncreases the compressor work
• CIncreases the turbine work
• DDecreases the thermal efficiency

Increases the thermal efficiency

Explanation:

### 17.In axial flow compressor, exit flow angle deviation from the blade angle is a function of

• BBlade camber and incidence angle
• CSpace-chord ratio
• DBlade camber and space-chord ratio

Explanation:

### 18.The air power of the compressor is also known as

• AIndicated power
• BBrake power
• CFrictional power
• DNone of these

Indicated power

Explanation:

### 19.To avoid moisture troubles, the compressed air main line should

• ARise gradually towards the point of use
• BDrop gradually towards the point of use
• CBe laid vertically
• DBe laid exactly horizontally

Drop gradually towards the point of use

Explanation:

### 20.The ratio of the discharge pressure to the inlet pressure of air is called

• ACompression ratio
• BExpansion ratio
• CCompressor efficiency
• DVolumetric efficiency