Compressors, Gas Turbines and Jet Engines MCQs

Question 1

Open cycle gas turbine works on

Accepted Answer

Brayton or Atkinson cycle

Answer

Rankine cycle

Answer

Carnot cycle

Answer

Ericsson cycle

Question 2

A turboprop is preferred to turbojet because

Accepted Answer

It has high power for take off

Answer

It has high propulsive efficiency at high speeds

Answer

It can fly at supersonic speeds

Answer

It can fly at high elevations

Question 3

In jet propulsion power unit, the inlet duct of diverging shape is used in order to

Accepted Answer

Convert kinetic energy of air into pressure energy

Answer

Collect more air

Answer

Provide robust structure

Answer

Beautify the shape

Question 4

Gas turbine cycle with regenerator

Accepted Answer

Increases thermal efficiency

Answer

Allows high compression ratio

Answer

Decreases heat loss is exhaust

Answer

Allows operation at very high altitudes

Question 5

The ratio of the net work obtained from the gas turbine plant to the turbine work is known as

Accepted Answer

Work ratio

Answer

Compression ratio

Answer

Pressure ratio

Answer

None of these

Question 6

The ratio of isentropic work to Euler work is known as

Accepted Answer

Pressure coefficient

Answer

Work coefficient

Answer

Polytropic reaction

Answer

Slip factor

Question 7

The ratio of isentropic work to Euler’s work is known as

Accepted Answer

Pressure coefficient

Answer

Compressor efficiency

Answer

Isentropic efficiency

Answer

Euler

Question 8

In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in ________ of the piston.

Accepted Answer

Two strokes

Answer

One stroke

Answer

Three strokes

Answer

Four strokes

Question 9

The overall thermal efficiency of an ideal gas turbine plant is (where r = Pressure ratio)

Accepted Answer

$$1 - {\left( {\frac{1}{{	ext{r}}}} ight)^{\frac{{\gamma - 1}}{\gamma }}}$$

Answer

$${{	ext{r}}^{\gamma - 1}}$$

Answer

$$1 - {{	ext{r}}^{\gamma - 1}}$$

Answer

$$1 - {\left( {\frac{1}{{	ext{r}}}} ight)^{\frac{\gamma }{{\gamma - 1}}}}$$