Compressors, Gas Turbines and Jet Engines MCQs

Question 1

After-cooler is used to

Accepted Answer

Cause moisture and oil vapour to drop out

Answer

Cool the air

Answer

Decrease the delivery temperature for ease in handling

Answer

Reduce volume

Question 2

An after-cooler is used to

Accepted Answer

Cause moisture and oil vapour to drop out

Answer

Remove impurities from air

Answer

Reduce volume of air

Answer

Cool the air

Question 3

Pick up the correct statement

Accepted Answer

Thrust in turbojet is produced by nozzle exit gases

Answer

Closed cycle gas turbine is an I.C engine

Answer

Gas turbine uses same working fluid over and over again

Answer

Ideal efficiency of closed cycle gas turbine plant is more than Carnot cycle efficiency

Question 4

Choose the correct statement

Accepted Answer

Gas turbine is capable of rapid start up and loading

Answer

Gas turbine requires lot of cooling water

Answer

Gas turbines has flat efficiency at part loads

Answer

Gas turbines have high standby losses and require lot of maintenance

Question 5

Pick up the correct statement

Accepted Answer

Gas turbine's blade will appear as impulse section at the hub and as a reaction section at tip

Answer

Large gas turbines use radial inflow turbines

Answer

Gas turbines have their blades similar to steam turbine

Answer

Gas turbines use both air and liquid cooling

Question 6

Pick up the correct statement

Accepted Answer

Gas turbine uses high air-fuel ratio to reduce outgoing temperature

Answer

Gas turbine uses low air-fuel ratio to economise on fuel

Answer

Gas turbine uses low air-fuel ratio to develop the high thrust required

Answer

All of the above

Question 7

A gas turbine used in air craft should have

Accepted Answer

Low weight and small frontal area

Answer

High h.p. and low weight

Answer

Small frontal area and high h.p.

Answer

High speed and high h.p.

Question 8

The compressor capacity with decrease in suction temperature

Accepted Answer

Increases

Answer

Decreases

Answer

Remain unaffected

Answer

May increase or decrease depending on compressor capacity

Question 9

In gas turbines, high thermal efficiency is obtained in

Accepted Answer

Closed cycle

Answer

Open cycle

Answer

Both of the above

Answer

Closed/open depending on other considerations