JETS 1-20

Question 1

What is the primary purpose of a jet in fluid machinery?
a) To increase pressure
b) To decrease pressure
c) To mix fluids
d) To provide propulsion

Answer 1

d) To provide propulsion

Question 2

Which of the following is true about a jet in fluid machinery?
a) It always operates at subsonic speeds
b) It can operate at supersonic speeds
c) It only operates in gases, not liquids
d) It has no effect on the surrounding fluid

Answer 2

b) It can operate at supersonic speeds

Question 3

What is the term for the phenomenon where a jet
entrains surrounding fluid?
a) Jetting
b) Contraction
c) Coanda effect
d) Viscosity

Answer 3

c) Coanda effect

Question 3

What type of jet is typically used in jet engines?
a) Incompressible jet
b) Subsonic jet
c) Supersonic jet
d) Laminar jet

Answer 3

c) Supersonic jet

Question 4

In a jet engine, what is the purpose of the convergentdivergent nozzle?
a) To increase pressure
b) To decrease temperature
c) To accelerate the flow to supersonic speeds
d) To decelerate the flow to subsonic speeds

Answer 4

c) To accelerate the flow to supersonic speeds

Question 5

Which law of fluid dynamics governs the behavior of
jets?
a) Bernoulli’s principle
b) Pascal’s law
c) Newton’s law of viscosity
d) Archimedes’ principle

Answer 5

a) Bernoulli’s principle

Question 6

What is meant by the term “choked flow” in the
context of jets?
a) The flow is completely stopped
b) The flow reaches the speed of sound
c) The flow is turbulent
d) The flow is laminar

Answer 6

b) The flow reaches the speed of sound

Question 7

What is the primary factor determining the velocity
of a jet?
a) Temperature of the fluid
b) Pressure of the fluid
c) Density of the fluid
d) Viscosity of the fluid

Answer 7

c) Density of the fluid

Question 8

Which of the following is NOT a characteristic of a
well-designed jet?
a) High velocity
b) Low turbulence
c) Wide spreading
d) Minimal entrainment

Answer 8

c) Wide spreading

Question 9

In a jet propulsion system, what is the purpose of the
diffuser?
a) To increase pressure
b) To decrease pressure
c) To increase velocity
d) To decrease velocity

Answer 9

a) To increase pressure

Question 10

Which type of jet is used in water jet cutting
machines?
a) Subsonic jet
b) Supersonic jet
c) Laminar jet
d) Incompressible jet

Answer 10

a) Subsonic jet
b) Supersonic jet

Question 11

What is the primary disadvantage of using a subsonic
jet for propulsion?
a) High fuel consumption
b) Low thrust
c) High noise levels
d) Limited range

Answer 11

b) Low thrust

Question 12

Which principle explains why a jet of water can bend
around a corner?
a) Bernoulli’s principle
b) Coanda effect
c) Pascal’s law
d) Archimedes’ principle

Answer 12

b) Coanda effect

Question 13

Which factor does NOT affect the trajectory of a jet?
a) Density of the jet
b) Angle of the jet
c) Velocity of the jet
d) Viscosity of the jet

Answer 13

d) Viscosity of the jet

Question 14

What is the main advantage of using a jet over a
propeller for propulsion?
a) Higher efficiency
b) Lower noise levels
c) Greater maneuverability
d) Longer service life

Answer 14

c) Greater maneuverability

Question 15

Which component of a jet engine is responsible for
compressing incoming air?
a) Turbine
b) Compressor
c) Nozzle
d) Combustor

Answer 15

b) Compressor

Question 16

What type of jet is commonly used in fire fighting
applications?
a) Supersonic jet
b) Subsonic jet
c) Incompressible jet
d) Laminar jet

Answer 16

a) Supersonic jet

Question 17

What is the term for the phenomenon where a jet
spreads out upon exiting a nozzle?
a) Contraction
b) Diffusion
c) Dilation
d) Dispersion

Answer 17

c) Dilation

Question 18

Which factor does NOT affect the thrust produced by
a jet engine?
a) Mass flow rate
b) Velocity of the jet
c) Pressure of the jet
d) Density of the jet

Answer 18

c) Pressure of the jet

Question 19

Which of the following is NOT a type of jet engine?
a) Turbojet
b) Ramjet
c) Pulsejet
d) Pistonjet

Answer 19

d) Pistonjet