Compressors, Gas Turbines And Jet Engines MCQ Questions & Answers

Compressors, Gas Turbines And Jet Engines MCQ Questions & Answers | Mechanical Engineering

Learn Compressors, Gas Turbines And Jet Engines MCQ questions & answers are available for a Mechanical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. Compressors, Gas Turbines And Jet Engines MCQ question is the important chapter for a Mechanical Engineering and GATE students. Page-6 section-2

The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature

A) 0.1% B) 0.5% C) 1% D) 5%

Discuss

Answer & Solution

Answer: Option C

Solution:

The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature 1%

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

Discuss

Answer & Solution

Answer: Option B

Solution:

The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is more

In a centrifugal compressor, the highest Mach number leading to shock wave in the fluid flow occurs at

A) Diffuser inlet radius B) Diffuser outlet radius C) Impeller inlet radius D) Impeller outlet radius

Discuss

Answer & Solution

Answer: Option B

Solution:

In a centrifugal compressor, the highest Mach number leading to shock wave in the fluid flow occurs at diffuser outlet radius

If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by

A) $$1 - {\text{K}} + {\text{K}}{\left( {\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}} \right)^{\frac{1}{{\text{n}}}}}$$ B) $$1 + {\text{K}} - {\text{K}}{\left( {\frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}} \right)^{\frac{1}{{\text{n}}}}}$$ C) $$1 - {\text{K}} + {\text{K}}{\left( {\frac{{{{\text{p}}_1}}}{{{{\text{p}}_2}}}} \right)^{\frac{{{\text{n}} - 1}}{{\text{n}}}}}$$ D) $$1 + {\text{K}} - {\text{K}}{\left( {\frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}} \right)^{\frac{{{\text{n}} - 1}}{{\text{n}}}}}$$

Discuss

Answer & Solution

Answer: Option B

Solution:

If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by $$1 + {\text{K}} - {\text{K}}{\left( {\frac{{{{\text{p}}_2}}}{{{{\text{p}}_1}}}} \right)^{\frac{1}{{\text{n}}}}}$$

Axial flow compressor has the following advantage over centrifugal compressor

A) Larger air handling ability per unit frontal area B) Higher pressure ratio per stage C) Aerofoil blades are used D) Higher average velocities

Discuss

Answer & Solution

Answer: Option A

Solution:

Axial flow compressor has the following advantage over centrifugal compressor Larger air handling ability per unit frontal area

The pressure ratio of an ideal vaned compressor with increase in mass flow rate

A) Increases B) Decreases C) Remain constant D) First decreases and then increases

Discuss

Answer & Solution

Answer: Option C

Solution:

The pressure ratio of an ideal vaned compressor with increase in mass flow rate remain constant

The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio

A) Increases B) Decreases C) First increases and then decreases D) First decreases and then increases

Discuss

Answer & Solution

Answer: Option A

Solution:

The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio Increases

A closed cycle gas turbine consists of a

A) Compressor B) Heating chamber C) Cooling chamber D) All of these

Discuss

Answer & Solution

Answer: Option D

Solution:

A closed cycle gas turbine consists of a -Compressor - Heating chamber -Cooling chamber

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

A) Start-stop motor B) Constant speed unloader C) Relief valve D) Variable speed

Discuss

Answer & Solution

Answer: Option A

Solution:

During base load operation, the best method of controlling compressor is Start-stop motor

The effective power of gas turbines is increased by adding the following in compressor

A) Ammonia and water vapour B) Carbon dioxide C) Nitrogen D) Hydrogen

Discuss

Answer & Solution

Answer: Option A

Solution:

The effective power of gas turbines is increased by adding Ammonia and water vapour following in compressor