Steam and Gas Turbines Multiple Choice Questions on “Usage of Gas Turbines in Jet Engines”.
1. Jet engines are classified into _______ types.
a) 5
b) 4
c) 3
d) 2
Answer: a
Clarification: Jet engines are classified into five types. They are
Turboshafts
Turbo jets
Turbo props
Turbofans
Propfan.
2. Jet engines works on ______ cycle.
a) brayton
b) dual
c) dual
d) otto
Answer: d
Clarification: Jet engines works on brayton cycle. Gasoline engines works on the otto cycle.
3. __________ bypass turbo fan engines are used in sub sonic flights.
a) Medium
b) Low
c) High
d) None of the mentioned
Answer: c
Clarification: High bypass turbo fan engines are used in sub sonic flights. High bypass turbo fan engines produce more power output.
4. Jet engines works from newton’s law of motion.
a) True
b) False
Answer: a
Clarification: Jet engines works from newton’s law of motion.
5. Turbofans gives more efficiency when the speed is ______ than the mach speed.
a) greater
b) less
c) equal
d) none of the mentioned
Answer: b
Clarification: Turbofans efficiency decreases when the speed exceeds the mach number.
6. _________ compressors are used in turbojets.
a) Axial
b) Radial
c) Axial & Radial
d) None of the mentioned
Answer: a
Clarification: Turbojets use axial or centrifugal compressors. Centrifugal compressors pressurizes the working fluid by centrifugal principle.
7. ____________ compressors can be used in turbojets.
a) Radial
b) Centrifugal
c) Radial & Centrifugal
d) None of the mentioned
Answer: b
Clarification: Both centrifugal or axial compressors can be used in turbo jets.
8. Internal energy in the fuel is converted into __________ of the exhaust in turbojets.
a) kinetic energy
b) pressure energy
c) kinetic & pressure energy
d) none of the mentioned
Answer: a
Clarification: Internal energy in the fuel is converted into kinetic energy of the exhaust in turbojets. Compressors convert internal energy of the fluid into velocity and hence kinetic energy is increased.
9. Gas generator core is used in turbo fans.
a) True
b) False
Answer: a
Clarification: Gas generator cores are used to convert internal energy of the gas to kinetic energy of the exhaust.
10. Jet engines have ________ shafts.
a) single
b) multiple
c) single or multiple
d) none of the mentioned
Answer: c
Clarification: Jet engines may have multiple shafts depending on their energy requirements.