2A651 Edition 2 Vol.2 Ure
Questions and Answers
- 1.
(201) An aircraft taxiing at a steady speed can be used to demonstrate
- A.
Bernoulli’s principle.
- B.
Newton’s first law of motion.
- C.
Newton’s second law of motion.
- D.
Newton’s third law of motion.
Correct Answer
B. Newton’s first law of motion.Explanation
An aircraft taxiing at a steady speed demonstrates Newton's first law of motion, also known as the law of inertia. According to this law, an object at rest or in motion will continue to stay in that state unless acted upon by an external force. In this case, the aircraft will continue to move at a steady speed unless a force, such as friction or air resistance, is applied to slow it down or bring it to a stop.Rate this question:
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- 2.
(201) Which law may you sum up with two words: action and reaction?
- A.
Bernoulli’s principle.
- B.
Newton’s first law of motion.
- C.
Newton’s second law of motion.
- D.
Newton’s third law of motion.
Correct Answer
D. Newton’s third law of motion.Explanation
Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that whenever an object exerts a force on another object, the second object exerts an equal and opposite force back on the first object. This law explains the relationship between the forces acting on two interacting objects, emphasizing that the forces are always equal in magnitude and opposite in direction.Rate this question:
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- 3.
(201) Which type of duct would decrease the velocity and increase the pressure of a gas as it passes through?
- A.
Elbow
- B.
Straight
- C.
Divergent
- D.
Convergent
Correct Answer
C. DivergentExplanation
A divergent duct is designed to gradually increase the cross-sectional area as the gas flows through it. This causes the velocity of the gas to decrease while the pressure increases. This type of duct is commonly used in applications where it is necessary to slow down the flow of a gas and increase its pressure, such as in certain types of exhaust systems or fluid handling systems.Rate this question:
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- 4.
(202) The ability to do work is the definition of
- A.
Energy.
- B.
Inertia.
- C.
Friction.
- D.
Velocity.
Correct Answer
A. Energy.Explanation
The ability to do work is often defined as energy. Energy is the capacity or ability to perform work, whether it is in the form of mechanical, thermal, electrical, or any other type of energy. In this context, inertia, friction, and velocity are not definitions of the ability to do work, making energy the correct answer.Rate this question:
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- 5.
(202) What does fuel for an engine represent?
- A.
Thrust produced
- B.
Efficiency ratio.
- C.
Potential energy.
- D.
Available horsepower.
Correct Answer
C. Potential energy.Explanation
Fuel for an engine represents potential energy. Potential energy is stored energy that can be converted into other forms, such as kinetic energy, to perform work. In the case of an engine, fuel is burned to release energy, which is then used to power the engine and produce thrust or horsepower. Therefore, the fuel in an engine represents the potential energy that can be harnessed to perform work and power the engine.Rate this question:
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- 6.
(203) The temperature of compressed air in a jet engine must be raised to
- A.
Increase energy.
- B.
Decrease energy.
- C.
Increase volume.
- D.
Decrease volume.
Correct Answer
A. Increase energy.Explanation
In a jet engine, the temperature of compressed air needs to be raised in order to increase its energy. This is because the increased temperature allows for better combustion of fuel, resulting in a more powerful and efficient engine. By increasing the energy of the compressed air, the jet engine can produce more thrust and propel the aircraft forward.Rate this question:
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- 7.
(203) Which section of a jet engine introduces and burns fuel?
- A.
Turbine.
- B.
Diffuser.
- C.
Compressor.
- D.
Combustion.
Correct Answer
D. Combustion.Explanation
The section of a jet engine that introduces and burns fuel is called the combustion section. In this section, fuel is mixed with compressed air and ignited, creating a high-temperature and high-pressure gas. This gas then expands and passes through the turbine, where it drives the compressor and provides thrust to the engine. The combustion section is a crucial part of the jet engine as it converts the chemical energy in the fuel into mechanical energy, which powers the aircraft.Rate this question:
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- 8.
(204) Which method of producing thrust does a turboprop engine use?
- A.
Using only the energy expended through the exhaust nozzle to propel the aircraft forward.
- B.
Using the same working fluid for propulsive force as that used within the engine.
- C.
Accelerating a large mass of air through a small velocity change.
- D.
Moving a small quantity of air through a large velocity change.
Correct Answer
C. Accelerating a large mass of air through a small velocity change.Explanation
A turboprop engine uses the method of accelerating a large mass of air through a small velocity change to produce thrust. This means that the engine takes in a large amount of air, compresses it, and then accelerates it through the propeller at a relatively low velocity. This creates a high amount of thrust, allowing the aircraft to move forward efficiently.Rate this question:
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- 9.
(204) Which type of horsepower is delivered to the propeller for useful work?
- A.
Brake
- B.
Indicated.
- C.
Frictional.
- D.
Equivalent shaft.
Correct Answer
A. BrakeExplanation
The correct answer is "Brake." Brake horsepower refers to the amount of power that is delivered to the propeller for useful work. It represents the actual power output of the engine and takes into account any losses due to friction or other factors.Rate this question:
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- 10.
(204) Which type of horsepower determines the performance of the engine-propeller combination?
- A.
Brake.
- B.
Indicated.
- C.
Frictional
- D.
Equivalent shaft.
Correct Answer
D. Equivalent shaft.Explanation
The type of horsepower that determines the performance of the engine-propeller combination is equivalent shaft horsepower. Equivalent shaft horsepower is a measure of the power output of an engine and is used to determine the power available to drive a propeller. It takes into account factors such as the engine's brake horsepower, losses due to friction, and other inefficiencies. Therefore, equivalent shaft horsepower is the most accurate measure of the engine-propeller combination's performance.Rate this question:
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- 11.
(205) The two fluids combined to make up common jet fuel are
- A.
Gasoline and oil.
- B.
Kerosene and oil.
- C.
Gasoline and water.
- D.
Kerosene and gasoline.
Correct Answer
D. Kerosene and gasoline.Explanation
The correct answer is kerosene and gasoline. Jet fuel is typically composed of a mixture of kerosene and gasoline. Kerosene provides the necessary energy and stability for the engine, while gasoline helps to improve the fuel's performance and cold weather capabilities. This combination of fuels ensures that the jet engine operates efficiently and reliably.Rate this question:
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- 12.
(206) Which is not a method of heat transfer?
- A.
Radiation
- B.
Convection
- C.
Penetration
- D.
Conduction.
Correct Answer
C. PenetrationExplanation
Penetration is not a method of heat transfer. The other three options, radiation, convection, and conduction, are all recognized methods of heat transfer. Radiation refers to the transfer of heat through electromagnetic waves, convection involves the transfer of heat through the movement of fluids or gases, and conduction is the transfer of heat through direct contact between two objects. Penetration, on the other hand, does not describe a recognized method of heat transfer.Rate this question:
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- 13.
(206) The air temperature of a jet engine gradually rises across the compressor to the diffuser outlet as a result of
- A.
Compression.
- B.
Fuel expansion.
- C.
Turbine discharge.
- D.
Ambient temperature increase.
Correct Answer
A. Compression.Explanation
The air temperature of a jet engine gradually rises across the compressor to the diffuser outlet as a result of compression. As the air passes through the compressor, it is compressed and its pressure and temperature increase. This is because the compressor squeezes the air, reducing its volume and increasing its density. This compression process causes the air temperature to rise. Therefore, the correct answer is compression.Rate this question:
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- 14.
(206) Where is the highest point of temperature reached in an engine?
- A.
Tailpipe.
- B.
Exhaust cone.
- C.
Turbine section.
- D.
Combustion section.
Correct Answer
D. Combustion section.Explanation
The highest point of temperature in an engine is reached in the combustion section. This is where the fuel and air mixture is ignited, resulting in the combustion process that generates the power needed to drive the engine. The combustion section is designed to withstand high temperatures and pressures, making it the location where the highest temperature is reached.Rate this question:
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- 15.
(207) Which engine component meters fuel for combustion?
- A.
P&D valve.
- B.
Fuel pump
- C.
Fuel control.
- D.
Fuel nozzles.
Correct Answer
C. Fuel control.Explanation
The fuel control component is responsible for metering the fuel for combustion in an engine. It regulates the amount of fuel that is injected into the combustion chamber based on factors such as engine speed and load. This ensures that the engine receives the correct amount of fuel for efficient and effective combustion.Rate this question:
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- 16.
(207) What happens to the energy that is absorbed by the turbine wheel?
- A.
50 percent is used for accessories.
- B.
60 percent is used for accessories.
- C.
The energy operates the anti-ice system.
- D.
The energy is returned to the compressor.
Correct Answer
D. The energy is returned to the compressor.Explanation
The energy that is absorbed by the turbine wheel is returned to the compressor. This means that the energy is recycled and used again in the system, rather than being wasted. This is an efficient way to utilize the energy and maximize its usage within the turbine system.Rate this question:
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- 17.
(207) On an average, what percent of all the energy produced by the fuel is required to maintain the engine operating cycle?
- A.
50
- B.
60
- C.
70
- D.
80
Correct Answer
B. 60Explanation
The correct answer is 60. This means that, on average, 60% of all the energy produced by the fuel is required to maintain the engine operating cycle. This suggests that a significant amount of energy is needed to keep the engine running efficiently.Rate this question:
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- 18.
(208) What directs the gases onto the first-stage turbine wheel blades in a jet engine?
- A.
Turbine wheel blades
- B.
Combustion chamber.
- C.
Turbine stator.
- D.
Flameholder.
Correct Answer
C. Turbine stator.Explanation
The turbine stator directs the gases onto the first-stage turbine wheel blades in a jet engine. The stator is a stationary component that is located between the combustion chamber and the turbine wheel. Its purpose is to guide and direct the flow of gases, ensuring that they pass through the turbine blades at the correct angle and velocity to maximize efficiency and power output.Rate this question:
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- 19.
(209) A jet engine derives its name from its design in that it uses
- A.
Turbo-superchargers within the engine
- B.
A turbine-type compressor to maintain power.
- C.
Nozzles which are called jet within the engine.
- D.
A gas-driven turbine wheel to drive its compressor.
Correct Answer
D. A gas-driven turbine wheel to drive its compressor.Explanation
A jet engine uses a gas-driven turbine wheel to drive its compressor. This means that the turbine wheel is powered by the flow of gas, which in turn drives the compressor. This design allows the engine to generate the necessary power and compression for the combustion process, which ultimately propels the aircraft forward. The other options mentioned in the question, such as turbo-superchargers and jet nozzles, are not directly related to the mechanism of driving the compressor in a jet engine.Rate this question:
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- 20.
(209) Vane-type fuel pumps used in jet engines are similar to
- A.
Sliding-vane air compressors
- B.
Piston pump air compressors.
- C.
Roots air compressors.
- D.
Turbo-superchargers.
Correct Answer
A. Sliding-vane air compressorsExplanation
Vane-type fuel pumps used in jet engines are similar to sliding-vane air compressors. Both of these devices use a set of vanes or blades that slide in and out of slots in a rotor to create a pumping action. This design allows for efficient and reliable fuel or air flow, making it suitable for high-performance applications like jet engines. The other options, piston pump air compressors, roots air compressors, and turbo-superchargers, do not have the same sliding-vane mechanism and therefore are not as similar to vane-type fuel pumps.Rate this question:
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- 21.
(210) Which condition reduces the efficiency of a centrifugal compressor?
- A.
Resultant velocity.
- B.
Tangential velocity.
- C.
Pressure pulsations.
- D.
Air mass leaving the impeller at great velocities.
Correct Answer
C. Pressure pulsations.Explanation
Pressure pulsations reduce the efficiency of a centrifugal compressor. When there are fluctuations in pressure, it can cause uneven loading on the impeller blades, leading to vibration and reduced performance. This can result in decreased efficiency and potentially damage the compressor components. Therefore, pressure pulsations are a condition that negatively affects the efficiency of a centrifugal compressor.Rate this question:
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- 22.
(211) Stationary vanes positioned between rotor discs in a compressor are used to
- A.
Direct air and increase pressure.
- B.
Direct hot gases rearward
- C.
Increase backup pressure.
- D.
Prolong compressor life.
Correct Answer
A. Direct air and increase pressure.Explanation
The stationary vanes positioned between rotor discs in a compressor are used to direct air and increase pressure. These vanes serve as a guide for the air as it flows through the compressor, ensuring that it is directed in the desired direction and increasing its pressure in the process. This is an important function in the compressor's operation, as it allows for the efficient compression of air or gas.Rate this question:
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- 23.
(211) The jet engine compressor that is cheaper to manufacture is the
- A.
Axial-flow type, because of its size.
- B.
Centrifugal type, because of its size.
- C.
Axial-flow type, because of its fewer parts.
- D.
Centrifugal type, because of its fewer parts.
Correct Answer
D. Centrifugal type, because of its fewer parts.Explanation
The centrifugal type of jet engine compressor is cheaper to manufacture because it has fewer parts compared to the axial-flow type. Having fewer parts reduces the complexity and cost of production, making it a more cost-effective option.Rate this question:
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- 24.
(212) The percentage of combustion efficiency of a gas turbine is usually between
- A.
60 and 70.
- B.
65 and 75.
- C.
75 and 95.
- D.
95 and 100.
Correct Answer
D. 95 and 100.Explanation
The percentage of combustion efficiency of a gas turbine refers to the amount of fuel that is effectively converted into useful energy. A higher percentage indicates a more efficient combustion process. The given correct answer states that the combustion efficiency of a gas turbine is usually between 95 and 100 percent. This means that the majority of the fuel is being effectively converted into energy, resulting in a highly efficient combustion process.Rate this question:
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- 25.
(212) What is the most probable cause of a flameout of a jet engine flying at 40,000 feet with a constant engine revolutions per minute (rpm) of 50 percent?
- A.
The rpm is too low.
- B.
A decrease in barometric pressure.
- C.
The failure of the breather pressurizing valve.
- D.
Excessive ducting of air from the compressor into the combustion chamber.
Correct Answer
A. The rpm is too low.Explanation
The most probable cause of a flameout of a jet engine flying at 40,000 feet with a constant engine rpm of 50 percent is that the rpm is too low. When the engine rpm is too low, it can lead to insufficient fuel combustion and result in a flameout, causing the engine to shut down.Rate this question:
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- 26.
(212) Carbon monoxide gas is poisonous and odorless, and has
- A.
A reddish color.
- B.
A greenish color.
- C.
A yellowish color.
- D.
No color.
Correct Answer
D. No color.Explanation
Carbon monoxide gas is poisonous and odorless, and it has no color. This means that it cannot be detected by our senses, making it extremely dangerous. The lack of color allows it to go unnoticed, increasing the risk of inhalation and poisoning. It is important to have proper detection systems in place to ensure the safety of individuals in environments where carbon monoxide may be present.Rate this question:
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- 27.
(213) What is the most chemically correct ratio for burning fuel in a combustion chamber?
- A.
10:1.
- B.
10:4.
- C.
15:1.
- D.
15:4.
Correct Answer
C. 15:1.Explanation
The most chemically correct ratio for burning fuel in a combustion chamber is 15:1. This means that for every 15 parts of air, there is 1 part of fuel. This ratio ensures that there is enough oxygen present in the combustion chamber to completely burn the fuel, resulting in efficient and clean combustion. A ratio of 10:1 or 10:4 would result in an excess of fuel, leading to incomplete combustion and the production of pollutants.Rate this question:
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- 28.
(213) The inner and outer surfaces of an annular-type combustion chamber are formed by
- A.
Interlocking stainless-steel bands.
- B.
The inner and outer diffuser case.
- C.
A forged steel casing.
- D.
Solid sheet metal.
Correct Answer
A. Interlocking stainless-steel bands.Explanation
The correct answer is interlocking stainless-steel bands. This means that the inner and outer surfaces of the annular-type combustion chamber are made up of stainless-steel bands that interlock with each other. This design allows for a secure and efficient combustion process within the chamber.Rate this question:
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- 29.
(213) Fuel that accumulates after a failed start is
- A.
Returned to the fuel control by tubes.
- B.
Drained overboard by a drain system.
- C.
Burned on the next start attempt.
- D.
Allowed to evaporate.
Correct Answer
B. Drained overboard by a drain system.Explanation
After a failed start, the fuel that accumulates is drained overboard by a drain system. This is done to remove the excess fuel and prevent any potential hazards or damage. Draining the fuel overboard ensures that it does not remain in the system and allows for a fresh start in the next attempt.Rate this question:
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- 30.
(213) The parts on a can-annular combustion section must be removed in a specific order because of the
- A.
Fuel nozzle.
- B.
Transition liner.
- C.
Combustion chamber outer case.
- D.
Combustion chamber crossover tubes.
Correct Answer
D. Combustion chamber crossover tubes.Explanation
The parts on a can-annular combustion section must be removed in a specific order because the combustion chamber crossover tubes are interconnected with other components and removing them first allows for easier access to the remaining parts.Rate this question:
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- 31.
(213) What is the most common type of fuel nozzle system?
- A.
Pressure-atomizing.
- B.
Fuel-blasting.
- C.
Fuel ejector.
- D.
Fuel tube.
Correct Answer
A. Pressure-atomizing.Explanation
The most common type of fuel nozzle system is pressure-atomizing. This system uses pressure to atomize the fuel into small particles, allowing for efficient combustion. This type of system is widely used in various applications, including automotive engines and industrial burners. It is preferred due to its ability to provide a fine spray of fuel, which promotes better fuel-air mixing and combustion efficiency.Rate this question:
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- 32.
(213) What type of flame speed are swirl-type fuel nozzles normally used to provide?
- A.
Low
- B.
High
- C.
Medium
- D.
Medium-high
Correct Answer
B. HighExplanation
Swirl-type fuel nozzles are typically used to provide a high flame speed. The swirling motion created by these nozzles helps to enhance the mixing of fuel and air, resulting in a more efficient and faster combustion process. This increased flame speed can be beneficial in applications where a rapid and intense combustion is desired, such as in certain types of burners or engines.Rate this question:
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- 33.
(214) What is placed in front of the rotating blades in a multiple-stage turbine engine?
- A.
Rotating vanes.
- B.
Inlet guide vanes.
- C.
Turbine rotating nozzles.
- D.
Turbine nozzle vane assembly.
Correct Answer
D. Turbine nozzle vane assembly.Explanation
The correct answer is turbine nozzle vane assembly. In a multiple-stage turbine engine, the turbine nozzle vane assembly is placed in front of the rotating blades. This assembly consists of vanes that direct the flow of exhaust gases onto the turbine blades, increasing the efficiency of the engine by optimizing the energy transfer from the hot gases to the rotating blades.Rate this question:
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- 34.
(215) The “fir tree” method of attaching turbine blades (buckets) to the turbine rotor disc is preferred because
- A.
Of the temperature differential between the turbine rotor disc and the blades.
- B.
It aids in preventing horizontal movement of the blades.
- C.
There is more blade tip shake during engine operation.
- D.
It aids in preventing axial movement of the bucket.
Correct Answer
A. Of the temperature differential between the turbine rotor disc and the blades.Explanation
The "fir tree" method of attaching turbine blades to the turbine rotor disc is preferred because it can accommodate the temperature differential between the rotor disc and the blades. This method allows for expansion and contraction of the blades due to temperature changes, ensuring a secure and stable attachment.Rate this question:
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- 35.
(215) Which method of attaching the turbine blades (buckets) to the turbine rotor disc is used most frequently?
- A.
Turbine blades fitted solidly into the rim of the rotor disc
- B.
Rivet placed in a hole through the base of the turbine blade.
- C.
Close-fitting shroud ring around the outer perimeter of the disc.
- D.
Series of grooves or notches broached in the rim of the turbine rotor disc.
Correct Answer
D. Series of grooves or notches broached in the rim of the turbine rotor disc.Explanation
The most frequently used method of attaching turbine blades to the turbine rotor disc is by using a series of grooves or notches broached in the rim of the disc. This method provides a secure and reliable connection between the blades and the disc, ensuring that they do not detach during operation. The grooves or notches allow for easy installation and removal of the blades when necessary. This method is widely used in turbine systems due to its effectiveness and practicality.Rate this question:
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- 36.
(216) The exhaust duct connects the turbine outlet and the
- A.
Fan duct
- B.
Jet nozzle
- C.
Fuel nozzle.
- D.
Bifurcated duct.
Correct Answer
B. Jet nozzleExplanation
The exhaust duct connects the turbine outlet and the jet nozzle. The jet nozzle is responsible for accelerating the exhaust gases and creating the propulsive force in a jet engine. Therefore, it makes sense for the exhaust duct to connect to the jet nozzle in order to direct the exhaust gases towards the rear of the engine and generate thrust.Rate this question:
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- 37.
(216) The purpose of the exhaust duct is to
- A.
Swirl exhaust gas-flow.
- B.
Equalize exhaust gas-flow
- C.
Straighten exhaust gas-flow.
- D.
Modulate exhaust gas-flow.
Correct Answer
C. Straighten exhaust gas-flow.Explanation
The purpose of the exhaust duct is to straighten exhaust gas-flow. This is important because exhaust gases often exit the engine in a turbulent and chaotic manner. By straightening the flow, the exhaust duct helps to improve the efficiency of the system and reduce turbulence, allowing for a smoother and more controlled release of exhaust gases.Rate this question:
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- 38.
(217) Which component in the augmentor creates local turbulence and reduces gas velocity?
- A.
Spraybars.
- B.
Flameholder.
- C.
Screech liner.
- D.
Fuel manifold.
Correct Answer
B. Flameholder.Explanation
The flameholder is the component in the augmentor that creates local turbulence and reduces gas velocity. It is designed to stabilize the flame by creating a recirculation zone where fuel and air mix, allowing for efficient combustion. The turbulence created by the flameholder helps to break up the flow of gases and prevent flame blowout. Spraybars, screech liner, and fuel manifold do not have the same function of creating turbulence and reducing gas velocity.Rate this question:
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- 39.
(218) How many different types of loads can be imposed on a jet engine bearing?
- A.
Two
- B.
Three
- C.
Four
- D.
Five
Correct Answer
B. ThreeExplanation
There are three different types of loads that can be imposed on a jet engine bearing.Rate this question:
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- 40.
(218) Before inspecting new jet engine bearings, you should
- A.
Separate the halves
- B.
Perform a spin check.
- C.
Apply a preservative coating.
- D.
Remove the preservative coating.
Correct Answer
D. Remove the preservative coating.Explanation
Before inspecting new jet engine bearings, it is necessary to remove the preservative coating. This is because the preservative coating is applied to protect the bearings during storage and transportation. Removing the coating allows for a thorough inspection of the bearings to ensure they are in proper working condition and free from any defects or damage.Rate this question:
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- 41.
(219) The most commonly used bearing removal tools include
- A.
Drift pipes and hammers.
- B.
Bearing pullers and hammers.
- C.
Drift pipes and arbor presses.
- D.
Arbor presses and bearing pullers.
Correct Answer
D. Arbor presses and bearing pullers.Explanation
Arbor presses and bearing pullers are the most commonly used tools for removing bearings. Arbor presses are used to apply pressure and force to remove the bearing from its housing, while bearing pullers are designed specifically to grip and pull out the bearing. These tools are effective and widely used in various industries for bearing removal purposes.Rate this question:
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- 42.
(220) Which type of defect appears on bearings as a result of bearing parts striking together?
- A.
Nicks.
- B.
Galling.
- C.
Grooves.
- D.
Scratches.
Correct Answer
A. Nicks.Explanation
When bearing parts strike together, it can cause small chips or nicks on the surface of the bearing. These nicks can be caused by various factors such as misalignment, excessive load, or improper lubrication. Nicks can lead to increased friction, reduced bearing performance, and ultimately, premature failure of the bearing. Therefore, nicks are a type of defect that can appear on bearings as a result of bearing parts striking together.Rate this question:
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- 43.
(220) Which type of defect appears on bearings as a result of small particles of foreign material becoming lodged between the rollers?
- A.
Pits
- B.
Bands
- C.
Grooves
- D.
Brinelling
Correct Answer
C. GroovesExplanation
When small particles of foreign material become lodged between the rollers of bearings, it can cause grooves to appear as a type of defect. These grooves are formed due to the abrasive action of the particles on the surfaces of the rollers. Over time, these grooves can lead to further damage and affect the performance and lifespan of the bearings.Rate this question:
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- 44.
(220) Which type of bearing defect results from inadequate lubrication?
- A.
Bands
- B.
Galling
- C.
Grooves
- D.
Brinelling
Correct Answer
B. GallingExplanation
Galling is a type of bearing defect that occurs due to inadequate lubrication. When there is not enough lubrication between the bearing surfaces, friction increases, causing the metal to seize and tear. This results in the formation of rough patches or galling on the bearing surfaces. Therefore, galling is the correct answer for the given question.Rate this question:
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- 45.
(221) Before you install separable bearings, you must ensure the
- A.
Rollers are serviceable.
- B.
Bearings are a matched set.
- C.
Rollers are properly positioned.
- D.
Parts are positioned and serviceable.
Correct Answer
B. Bearings are a matched set.Explanation
Before installing separable bearings, it is important to ensure that the bearings are a matched set. This means that the bearings are specifically designed to work together and have the same specifications. Using mismatched bearings can result in improper functioning and potential damage to the equipment. Therefore, it is crucial to check that the bearings are a matched set before installation.Rate this question:
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- 46.
(221) Of the following, the recommended method of expanding a bearing race before installation is to use a
- A.
Hot-oil bath.
- B.
Coal furnace
- C.
Hydraulic-oil bath.
- D.
Oscillating heater.
Correct Answer
A. Hot-oil bath.Explanation
The recommended method of expanding a bearing race before installation is to use a hot-oil bath. This method involves heating the bearing race in a bath of hot oil, which causes the metal to expand. This allows for easier installation of the bearing race onto the shaft or housing. The hot oil provides a uniform and controlled heat source, ensuring that the bearing race expands evenly and avoids any damage or distortion.Rate this question:
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- 47.
(222) Which component reduces the engine rotor speed to the revolutions per minute (rpm) required for accessories?
- A.
Step motors.
- B.
Reduction motor.
- C.
Reduction geartrain.
- D.
Gear case drive assembly.
Correct Answer
C. Reduction geartrain.Explanation
The reduction geartrain is responsible for reducing the engine rotor speed to the required revolutions per minute (rpm) for accessories. It is a system of gears that work together to decrease the speed and increase the torque of the engine, allowing it to power various accessories efficiently.Rate this question:
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- 48.
(222) The reduction gearbox on an F100–PW–220 engine reduces speed between the main fuel gear pump and the engine-driven main gearbox by
- A.
45 percent.
- B.
33 percent.
- C.
46 percent.
- D.
52 percent.
Correct Answer
D. 52 percent.Explanation
The reduction gearbox on an F100-PW-220 engine reduces the speed between the main fuel gear pump and the engine-driven main gearbox by 52 percent.Rate this question:
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- 49.
(223) To cause an accessory in a jet engine to operate at its most optimum speed, design engineers must
- A.
Change the gear ratio.
- B.
Change the governor setting.
- C.
Install an additional set of drive gears.
- D.
Adjust the operating speed of the engine.
Correct Answer
A. Change the gear ratio.Explanation
To cause an accessory in a jet engine to operate at its most optimum speed, design engineers must change the gear ratio. This means altering the ratio between the input and output gears in the system, which will result in a change in the speed of the accessory. By adjusting the gear ratio, the engineers can ensure that the accessory operates at the most efficient speed for optimal performance. This is important for maintaining the overall efficiency and functionality of the jet engine.Rate this question:
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- 50.
(223) On a F108 engine, which component serves as the mechanical coupling between the compressor rotor and the transfer gearbox (TGB)?
- A.
Power take-off (PTO) drive shaft.
- B.
Accessory gearbox (AGB).
- C.
Inlet gearbox (IGB).
- D.
Radial drive shaft.
Correct Answer
C. Inlet gearbox (IGB).Explanation
The Inlet gearbox (IGB) serves as the mechanical coupling between the compressor rotor and the transfer gearbox (TGB) on a F108 engine.Rate this question:
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Mar 20, 2023Quiz Edited by
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Oct 26, 2012Quiz Created by
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