Compressors, Gas Turbines and Jet Engines MCQs

Question 1

The compressed air may be used

Accepted Answer

All of the above

Answer

In gas turbine plants

Answer

For operating pneumatic drills

Answer

In starting and supercharging of I.C. engines

Question 2

The overall isothermal efficiency of the compressor is defined as the ratio of

Accepted Answer

Isothermal power to the shaft power or B.P. of the motor or engine required to drive the compressor

Answer

Work required to compress the air isothermally to the actual work required to compress the air for the same pressure ratio

Answer

Volume of free air delivery per stroke to the swept volume of the piston

Answer

Isentropic power to the power required to drive the compressor

Question 3

The overall isothermal efficiency of compressor is defined as the ratio of

Accepted Answer

Isothermal h.p. to the BHP of motor

Answer

Isothermal h.p. to adiabatic h.p.

Answer

Power to drive compressor to isothermal h.p.

Answer

Work to compress air isothermally to work for actual compression

Question 4

The work ratio of a gas turbine plant is defined as the ratio of

Accepted Answer

Net work output and work done by turbine

Answer

Net work output and heat supplied

Answer

Actual heat drop and isentropic heat drop

Answer

Net work output and isentropic heat drop

Question 5

The maximum propulsion efficiency of a turbojet is attained at around following speed

Accepted Answer

2400 km/hr

Answer

550 km/hr

Answer

1050 km/hr

Answer

1700 km/hr

Question 6

The minimum work required for a three stage reciprocating air compressor is ________ the work required for each stage.

Accepted Answer

Three times

Answer

Equal to

Answer

Double

Answer

Six times

Question 7

The working fluid in a turbine is

Accepted Answer

In a single phase

Answer

In two phases

Answer

In three phases

Answer

In the form of air and water mixture

Question 8

High air-fuel ratio is used in gas turbines

Accepted Answer

To reduce the exit temperature

Answer

To increase the output

Answer

To increase the efficiency

Answer

To save fuel

Question 9

An air receiver is to be placed outside. Should it be placed in

Accepted Answer

Shade

Answer

Sun

Answer

Rain

Answer

Enclosed room