Compressors, Gas Turbines and Jet Engines MCQs

Question 1

The criterion of the thermodynamic efficiency for rotary compressor is

Accepted Answer

Isentropic compression

Answer

Isothermal compression

Answer

Polytropic compression

Answer

None of the above

Question 2

Producer gas is produced by

Accepted Answer

Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast

Answer

Carbonisation of coal

Answer

Passing steam over incandescent coke

Answer

Passing air and a large amount of steam over waste coal at about 65°C

Question 3

Water gas is produced by

Accepted Answer

Passing steam over incandescent coke

Answer

Carbonisation of coal

Answer

Passing air and a large amount of steam over waste coal at about 65°C

Answer

Partial combustion of coal, eke, anthracite coal or charcoal in a mixed air steam blast

Question 4

Which of the following statement is wrong?

Accepted Answer

None of the above

Answer

In a two stage reciprocating air compressor with complete intercooling, maximum work is saved

Answer

The minimum work required for a two stage reciprocating air compressor is double the work required for each stage

Answer

The ratio of the volume of free air delivery per stroke to the swept volume of the piston is called volumetric efficiency

Question 5

Work ratio of a gas turbine may be improved by

Accepted Answer

Both (A) and (C) above

Answer

Decreasing the compression work

Answer

Increasing the compression work

Answer

Increasing the turbine work

Question 6

The gas in cooling chamber of a closed cycle gas turbine is cooled at

Accepted Answer

Constant pressure

Answer

Constant volume

Answer

Constant temperature

Answer

None of these

Question 7

In a turbo jet engine, subsequent to heat addition to compressed air, to get the power output, the working substance is expanded in

Accepted Answer

Turbine blades, which is essentially an isentropic process

Answer

Exit nozzle, which is a constant volume process

Answer

Exit nozzle, which is essentially an isentropic process

Answer

Turbine blades, which is a constant volume process

Question 8

Gas turbine as compared to internal combustion engine

Accepted Answer

All of these

Answer

Can be driven at a very high speed

Answer

Produces uniform torque

Answer

Has more efficiency

Question 9

The mean effective pressure of the compressor is the

Accepted Answer

None of the above

Answer

Actual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions

Answer

Volume of air delivered by the compressor

Answer

Volume of air sucked by the compressor during its suction stroke