JETS 21-40

Question 1

In a turbofan engine, what is the purpose of the fan?
a) To compress air
b) To cool the engine
c) To increase thrust
d) To provide propulsion

Answer 1

c) To increase thrust

Question 2

Which of the following is a disadvantage of using a
supersonic jet for propulsion?
a) High fuel consumption
b) Limited top speed
c) Poor maneuverability
d) Excessive noise levels

Answer 2

d) Excessive noise levels

Question 3

What type of jet is commonly used in inkjet printers?
a) Subsonic jet
b) Supersonic jet
c) Laminar jet
d) Incompressible jet

Answer 3

a) Subsonic jet

Question 4

What is the primary advantage of using a laminar jet?
a) High thrust
b) Low noise levels
c) Narrow spreading
d) Minimal entrainment

Answer 4

d) Minimal entrainment

Question 5

Which component of a jet engine is responsible for
igniting the fuel-air mixture?
a) Compressor
b) Nozzle
c) Turbine
d) Combustor

Answer 5

d) Combustor

Question 6

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

Answer 6

a) To increase pressure

Question 7

What type of jet is used in rocket propulsion?
a) Subsonic jet
b) Supersonic jet
c) Incompressible jet
d) Exhaust jet

Answer 7

b) Supersonic jet

Question 8

Which factor does NOT affect the efficiency of a jet
engine?
a) Temperature of the surroundings
b) Altitude
c) Humidity
d) Diameter of the nozzle

Answer 8

d) Diameter of the nozzle

Question 9

What is the term for the ratio of the actual velocity of
a jet to the velocity of sound?
a) Mach number
b) Reynolds number
c) Froude number
d) Weber number

Answer 9

a) Mach number

Question 10

What type of jet is commonly used in sandblasting
applications?
a) Subsonic jet
b) Supersonic jet
c) Incompressible jet
d) Abrasive jet

Answer 10

d) Abrasive jet

Question 11

What phenomenon allows a jet engine to produce
thrust?
a) Newton’s Third Law of Motion
b) Archimedes’ Principle
c) Pascal’s Law
d) Boyle’s Law

Answer 11

a) Newton’s Third Law of Motion

Question 12

What type of jet is used in cooling systems for gas
turbines?
a) Subsonic jet
b) Supersonic jet
c) Incompressible jet
d) Coolant jet

Answer 12

d) Coolant jet

Question 13

Which factor affects the range of a jet-powered
aircraft?
a) Thrust-to-weight ratio
b) Wing span
c) Length of the fuselage
d) Density of the fuel

Answer 13

a) Thrust-to-weight ratio

Question 14

What is the primary purpose of a jet nozzle?
a) To decrease pressure
b) To increase velocity
c) To mix fluids
d) To provide stability

Answer 14

b) To increase velocity

Question 15

In a ramjet engine, how is the incoming air
compressed?
a) By a compressor
b) By the forward motion of the engine
c) By a diffuser
d) By a convergent-divergent nozzle

Answer 15

b) By the forward motion of the engine

Question 16

What is the term for the ratio of the mass flow rate of
the jet to the mass flow rate of the surrounding fluid?
a) Jet ratio
b) Entrainment ratio
c) Thrust ratio
d) Efficiency ratio

Answer 16

b) Entrainment ratio

Question 17

What is the primary disadvantage of using a water jet
for propulsion in marine applications?
a) High energy consumption
b) Limited speed
c) Environmental impact
d) Corrosion of the nozzle

Answer 17

b) Limited speed

Question 18

Which of the following statements is true about a
convergent nozzle?
a) It decreases the velocity of the jet
b) It increases the pressure of the jet
c) It accelerates the flow of the jet
d) It decreases the mass flow rate of the jet

Answer 18

c) It accelerates the flow of the jet

Question 19

Which of the following is NOT a type of jet engine
cycle?
a) Brayton cycle
b) Otto cycle
c) Rankine cycle
d) Stirling cycle

Answer 19

b) Otto cycle

Question 20

In a pulsejet engine, what causes the periodic
combustion process?
a) Oscillating air pressure
b) Turbine rotation
c) Pulsating fuel injection
d) Thermal expansion of the combustion chamber

Answer 20

a) Oscillating air pressure