1.
What component on the New Generation Heater activates the HCU?
Correct Answer
C. Heat control switch
Explanation
The heat control switch is the component on the New Generation Heater that activates the HCU. This switch is responsible for controlling the temperature settings of the heater and when it is turned on, it sends a signal to the HCU to start the heating process. The oil pressure switch is not directly involved in activating the HCU, the burner control unit is responsible for regulating the fuel flow to the burner, and the thermostatic sensor is used to measure the temperature of the heater but does not directly activate the HCU.
2.
The HCU on the New Generation heater starts the main air fan for output air when
Correct Answer
D. The inside temp reaches 140 degrees F
Explanation
The correct answer is that the inside temperature reaches 140 degrees F. This means that the main air fan of the New Generation heater will start functioning once the temperature inside the heater reaches 140 degrees F. The other options mentioned, such as selecting a heat setting, establishing a constant flame, or the temperature gauge reading COOL, do not indicate when the main air fan will start.
3.
When should you use a starting aids to start the New Generation Heater?
Correct Answer
B. Never, as it will result in serious engine damage
Explanation
Using starting aids to start the New Generation Heater can result in serious engine damage. Therefore, it is advised to never use starting aids for this purpose.
4.
Repair of ground heater equipment should never be attempted
Correct Answer
C. Unless accurate technical data is available
Explanation
Repair of ground heater equipment should never be attempted unless accurate technical data is available. This is because accurate technical data provides the necessary information and instructions to safely and effectively repair the equipment. Without accurate technical data, there is a risk of causing further damage or injury to oneself or others. It is important to have access to the correct information and guidelines before attempting any repairs on ground heater equipment.
5.
The amount of heat required to raise the temp of one pound of a substance one degree Fahrenheit is known as
Correct Answer
A. British Thermal Unit
Explanation
The correct answer is British Thermal Unit. British Thermal Unit (BTU) is a unit of measurement for heat energy. It represents the amount of heat required to raise the temperature of one pound of a substance by one degree Fahrenheit. Sensible heat refers to the heat that can be sensed or measured, specific heat is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius, and latent heat is the heat absorbed or released during a phase change without a change in temperature.
6.
Heat that can be felt and added or subtracted to a substance without changing its state is called
Correct Answer
D. Sensible heat
Explanation
Sensible heat refers to the heat that can be felt and added or subtracted to a substance without changing its state. Unlike latent heat, which is associated with phase changes, sensible heat affects the temperature of a substance. Specific heat, on the other hand, is the amount of heat required to raise the temperature of a substance by a certain amount. Therefore, the correct answer is sensible heat.
7.
Heat added to a gaseous substance is known as
Correct Answer
C. Super heat
Explanation
Superheat refers to the heat added to a gaseous substance beyond its boiling point or saturation temperature. It is the amount of heat energy required to completely convert a substance from its liquid state to a gaseous state at a constant temperature. Sensible heat refers to the heat added or removed from a substance that causes a change in its temperature, while specific heat is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. Latent heat, on the other hand, is the heat energy absorbed or released during a phase change without a change in temperature.
8.
The relationship between pressure and the boiling point of a liquid is seen when
Correct Answer
A. Pressure increases, it raises the boiling point
Explanation
When pressure increases, it raises the boiling point of a liquid. This is because an increase in pressure compresses the gas phase above the liquid, making it harder for bubbles to form and escape. As a result, more heat is required to overcome the increased pressure and reach the boiling point. Conversely, when pressure decreases, it lowers the boiling point because there is less resistance for bubbles to form and escape, requiring less heat to reach the boiling point.
9.
The factors that have the greatest bearing on the temperature of a refrigerant are the boiling of a liquid and the amount of heat applied and the
Correct Answer
D. Pressure applied
Explanation
The pressure applied is the factor that has the greatest bearing on the temperature of a refrigerant. When pressure is applied to a refrigerant, it affects its boiling point and the amount of heat required for it to change from a liquid to a vapor. Increasing the pressure raises the boiling point and requires more heat to be applied for the refrigerant to reach its boiling point. Conversely, decreasing the pressure lowers the boiling point and requires less heat. Therefore, the pressure applied is a crucial factor in determining the temperature of a refrigerant.
10.
What component on the MA-3D air conditioner allows the operator to control the overall volume of air leaving the unit?
Correct Answer
B. Airflow control switch
Explanation
The airflow control switch on the MA-3D air conditioner allows the operator to control the overall volume of air leaving the unit. This switch regulates the amount of air that is being circulated and allows the operator to adjust it according to their preference. By turning the airflow control switch, the operator can increase or decrease the amount of air coming out of the unit, thereby controlling the overall volume of air.
11.
What type of solution is used in the MA-3D aftercooler system to carry heat away from the conditioned air stream?
Correct Answer
D. Ethylene glycol/water solution
Explanation
The MA-3D aftercooler system uses an ethylene glycol/water solution to carry heat away from the conditioned air stream. This solution is commonly used as a coolant in various systems due to its high heat capacity and low freezing point. By circulating the ethylene glycol/water solution through the aftercooler system, heat is absorbed from the air stream and transferred to the solution, effectively cooling the air before it is released. This solution is preferred over other options like liquid or gaseous refrigerant or pure water solution due to its superior heat transfer properties.
12.
Refrigerant that leaves the evaporator coil in the MA-3D air conditioner is further changed into a
Correct Answer
A. Low pressure gas
Explanation
The refrigerant that leaves the evaporator coil in the MA-3D air conditioner is further changed into a low pressure gas. This means that the refrigerant, after absorbing heat from the surrounding air in the evaporator coil, undergoes a phase change from a liquid to a gas while maintaining a low pressure. This low pressure gas is then compressed and condensed in the compressor and condenser coils to release heat and cool down before being circulated back to the evaporator coil to repeat the cooling cycle.
13.
After the refrigerant leaves the compressor on the MA-3D air conditioner, it passes through the oil separator and into the
Correct Answer
B. Condenser coils
Explanation
After the refrigerant leaves the compressor, it goes through the oil separator to remove any oil that may have mixed with it. Then, it enters the condenser coils. The condenser coils are responsible for transferring heat from the refrigerant to the surrounding air, causing the refrigerant to condense into a liquid. This process releases heat and allows the refrigerant to cool down. Therefore, the correct answer is condenser coils.
14.
When starting the MA-3D air conditioner, hold the safety override switch until
Correct Answer
A. 30 psi oil pressure is registered on the engine oil pressure guage
Explanation
The correct answer is 30 psi oil pressure is registered on the engine oil pressure gauge. This means that the air conditioner should only be started once the engine has reached a sufficient oil pressure of 30 psi. This ensures that the engine is properly lubricated and ready to operate. Releasing the start switch, warming up the engine, or the engine starting are not the correct conditions for starting the air conditioner.
15.
What component on the MA-3D air conditioner receives input from sensors for suction pressure and leaving air temperature?
Correct Answer
C. Temperature controller
Explanation
The temperature controller on the MA-3D air conditioner receives input from sensors for suction pressure and leaving air temperature. This component is responsible for monitoring and adjusting the temperature of the air being circulated by the air conditioner. By receiving input from sensors, the temperature controller can accurately regulate the cooling process to maintain a desired temperature in the room.
16.
What componenet on the MA-3D air conditioner shuts off the compressor when the suction pressure drops below 5 PSI?
Correct Answer
C. Temperature controller
Explanation
The temperature controller on the MA-3D air conditioner shuts off the compressor when the suction pressure drops below 5 PSI. This component is responsible for monitoring and controlling the temperature of the system. When the suction pressure drops below the specified level, it indicates a potential issue with the system, and the temperature controller shuts off the compressor to prevent further damage or malfunction. This helps maintain the efficiency and performance of the air conditioner.
17.
What type of refrigeration system leak occurs when the pressure within the system is less than atmospheric pressure?
Correct Answer
A. Inward leaks
Explanation
Inward leaks occur when the pressure within the refrigeration system is less than atmospheric pressure. This means that air or other substances from the outside are being drawn into the system, causing a leak. Vacuum leaks, pressure leaks, and outward leaks are not correct because they do not accurately describe the type of leak that occurs when the pressure within the system is less than atmospheric pressure.
18.
When performing refrigerant recovery, be sure
Correct Answer
A. To use vacuum pumps
Explanation
When performing refrigerant recovery, it is important to use vacuum pumps. Vacuum pumps are used to remove air and moisture from the refrigerant system, ensuring that the system is free from contaminants. This helps to maintain the efficiency and performance of the refrigerant system. By using vacuum pumps, any remaining air and moisture can be eliminated, reducing the risk of damage to the system and ensuring proper operation.
19.
The air cycle machine of an A/M32C-10D air conditioner consists of
Correct Answer
D. An expansion turbine and a compressor fan
Explanation
The air cycle machine of an A/M32C-10D air conditioner consists of an expansion turbine and a compressor fan. The expansion turbine is responsible for expanding the compressed air, which cools it down. The compressor fan then takes in the cooled air and compresses it, increasing its pressure. This process helps to cool the air and maintain the desired temperature inside the air conditioner.
20.
The component of a A/M32C-10D air conditioner that extracts energy fromt eh bleed air on the air cycle machine is the
Correct Answer
C. Expansion turbine
Explanation
The expansion turbine is the component of the A/M32C-10D air conditioner that extracts energy from the bleed air on the air cycle machine. This turbine takes in the high-pressure, high-temperature air and expands it, converting the thermal energy into mechanical energy. This mechanical energy is then used to drive the air cycle machine, which cools and conditions the air for use in the air conditioning system. The expansion turbine plays a crucial role in the energy extraction process and is responsible for the efficient operation of the air conditioner.
21.
The compressor switch on the ACE 802S must be held in the HOLD position when engaging the compressor in order to
Correct Answer
B. Allow the oil and discharge pressures to stabilize
Explanation
When engaging the compressor on the ACE 802S, holding the switch in the HOLD position allows the oil and discharge pressures to stabilize. This is important because the compressor needs stable oil pressure to function properly and prevent any damage. Stabilizing the discharge pressure ensures that the compressor operates efficiently and effectively.
22.
What action occurs in the evaporator of the ACE 802S air conditioner?
Correct Answer
B. Boiling refrigerant absorbs heat from the air stream
Explanation
In the evaporator of the ACE 802S air conditioner, the action that occurs is that the boiling refrigerant absorbs heat from the air stream. This is the process by which the refrigerant evaporates and extracts heat from the surrounding air, causing the air to cool down.
23.
What system on the ACE 802S air conditioner "supercharges" the compressor?
Correct Answer
C. Vapor injection
Explanation
Vapor injection is the system on the ACE 802S air conditioner that "supercharges" the compressor. This system injects vapor into the compressor, which increases its efficiency and performance. By introducing vapor into the compressor, it helps to cool down the motor and prevents overheating. This process allows the compressor to operate at a higher capacity, providing more cooling power and improving the overall efficiency of the air conditioner.
24.
What valve must be opened prior to starting the engine on the ACE 802S?
Correct Answer
A. Air shutoff
Explanation
The air shutoff valve must be opened prior to starting the engine on the ACE 802S. This valve controls the flow of air into the engine and needs to be open in order for the engine to receive the necessary air for combustion. Without the air shutoff valve being opened, the engine will not be able to start and run properly.
25.
What must be accomplished to avoid damage prior to operating the ACE 802S air conditioner in the HEATING mode after COOLING mode operation?
Correct Answer
A. Permit refrigerant pressure to equalize
Explanation
To avoid damage prior to operating the ACE 802S air conditioner in the HEATING mode after COOLING mode operation, it is necessary to permit refrigerant pressure to equalize. This is important because when switching between modes, the refrigerant pressure needs to stabilize before starting the heating operation. If the pressure is not allowed to equalize, it can cause stress on the system and potentially lead to damage. Therefore, it is crucial to permit refrigerant pressure to equalize before operating the air conditioner in the HEATING mode.
26.
In troubleshooting, what is the first step that must be completed when a unit comes in with a write-up in the forms?
Correct Answer
D. Recognize the write-up as a malfunction
Explanation
The first step that must be completed when a unit comes in with a write-up in the forms is to recognize the write-up as a malfunction. This means acknowledging that there is an issue or problem reported by the unit and understanding that it needs to be addressed. Once the write-up is recognized as a malfunction, further steps can be taken to investigate and resolve the issue, such as performing a service inspection, isolating the problem, and performing an operational check.
27.
How can a restriction in a refrigerant system be identified?
Correct Answer
A. Frosting at the outlet
Explanation
A restriction in a refrigerant system can be identified by observing frosting at the outlet. When there is a restriction, the flow of refrigerant is hindered, causing a decrease in pressure and temperature. This leads to the formation of frost on the outlet. Therefore, the presence of frosting indicates that there is a restriction in the system.
28.
Oil in the rotary vane compressor
Correct Answer
C. Forms a seal between the vanes and the stator
Explanation
The oil in the rotary vane compressor forms a seal between the vanes and the stator. This is important because it prevents any leakage of air or gas between the vanes and the stator, ensuring efficient compression. Without this seal, the compressor would not be able to build up high pressure and function properly.
29.
What provides pressurized oil to the rotor blades of the MC-2A rotary sliding vane compressor?
Correct Answer
C. Rotor shaft
Explanation
The rotor shaft provides pressurized oil to the rotor blades of the MC-2A rotary sliding vane compressor.
30.
On the MC-2A rotary sliding vane compressor, the minimum pressure valve does all of the following except
Correct Answer
B. Ensure minimum pressure to the condensate drain
Explanation
The MC-2A rotary sliding vane compressor's minimum pressure valve is responsible for ensuring minimum pressure within the oil chamber, preventing receiver air from flowing back to the compressor by working as a check valve, and increasing the efficiency of the felt pads by ensuring they receive a constant minimum air pressure. However, it does not have a direct role in ensuring minimum pressure to the condensate drain.
31.
What medium is used to cool the MC-2A rotary vane compressor?
Correct Answer
A. Oil
Explanation
The MC-2A rotary vane compressor is cooled using oil. Oil is commonly used in compressors as a cooling medium because it has excellent heat transfer properties. It absorbs the heat generated during compression and carries it away, preventing the compressor from overheating. Oil also helps lubricate the moving parts of the compressor, reducing friction and wear. Using oil as a cooling medium ensures efficient and reliable operation of the MC-2A rotary vane compressor.
32.
What is the air output of the MC-2A rotary sliding vane compressor?
Correct Answer
D. Low volume, low pressure
Explanation
The MC-2A rotary sliding vane compressor has a low volume, low pressure air output. This means that it delivers a smaller amount of air at a lower pressure. This type of compressor is typically used for applications that require a steady flow of air at a lower pressure, such as in small pneumatic tools or airbrushing.
33.
The valves on a reciprocating compressor are operated by
Correct Answer
A. AtmospHeric pressure
Explanation
The valves on a reciprocating compressor are operated by atmospheric pressure. In a reciprocating compressor, the valves are responsible for controlling the flow of gases in and out of the cylinder. Atmospheric pressure plays a crucial role in this process. When the piston moves down during the suction stroke, the pressure inside the cylinder decreases below atmospheric pressure. This pressure difference causes the inlet valve to open, allowing the gas to enter the cylinder. Similarly, during the compression stroke, the pressure inside the cylinder increases above atmospheric pressure, causing the outlet valve to open and release the compressed gas. Therefore, atmospheric pressure is the driving force behind the operation of the valves in a reciprocating compressor.
34.
Oil-moisture traps are required on a multi-stage reciprocating compressor to
Correct Answer
D. Remove moisture from the compressed air
Explanation
Oil-moisture traps are necessary on a multi-stage reciprocating compressor to remove moisture from the compressed air. As the air is compressed, it tends to hold more moisture, which can cause damage to the compressor and downstream equipment. The oil-moisture traps work by capturing and separating the moisture from the compressed air, preventing it from entering the system. This helps to ensure the efficiency and longevity of the compressor and other components by eliminating the potential for corrosion and water damage.
35.
During an inspection on an LN2 cart, you should look at all of the following except the
Correct Answer
B. Engine oil level
Explanation
During an inspection on an LN2 cart, it is important to check various components for their condition and functionality. The brake assembly should be inspected to ensure it is in good working order. The unit's cleanliness is also crucial to maintain proper operation. Additionally, the front end alignment should be checked to ensure the cart's stability and maneuverability. However, the engine oil level is not directly related to the cart's inspection as it does not impact its immediate functionality or safety. Therefore, the engine oil level does not need to be considered during the inspection.
36.
When LOX carts are being transported, what position should the vent valve be in?
Correct Answer
B. Closed
Explanation
During the transportation of LOX carts, the vent valve should be in the closed position. This is because LOX (Liquid Oxygen) is highly reactive and can cause combustion or explosion in the presence of certain materials. By keeping the vent valve closed, it helps to prevent any accidental release or leakage of the LOX, ensuring the safety of the transportation process.
37.
How is the air compressor in the SCNSC categorized?
Correct Answer
A. High-pressure
Explanation
The air compressor in the SCNSC is categorized as high-pressure because it is designed to generate and deliver air at a high pressure level. This means that it can produce compressed air with a greater force, making it suitable for applications that require high-pressure air, such as pneumatic tools or industrial processes that demand a strong air flow.
38.
What component on the SGNSC removes nitrogen from the ambient air?
Correct Answer
D. Separation membrane
Explanation
The separation membrane is the component on the SGNSC that removes nitrogen from the ambient air. This membrane is designed to selectively allow the passage of nitrogen molecules while blocking other gases. By using this membrane, nitrogen can be separated from the air, allowing for the production of nitrogen gas.
39.
To start the SGNSC, the operator must place the ignition switch in the start position for no more than
Correct Answer
B. 10 seconds
Explanation
To start the SGNSC (Starter-Generator Non-Start Control), the operator must place the ignition switch in the start position for no more than 10 seconds. This time duration is important to prevent damage to the starter-generator system. If the ignition switch is held in the start position for too long, it can cause overheating and potential failure of the starter-generator. Therefore, it is crucial to follow the recommended time limit of 10 seconds to ensure proper functioning and longevity of the SGNSC.
40.
At what storage cylinder pressure, in psig, should the SGNSC nitrogen booster compressor stop?
Correct Answer
C. 4400 psig
Explanation
The SGNSC nitrogen booster compressor should stop at a storage cylinder pressure of 4400 psig.
41.
The proper level of the guage of the hydraulic reservoir should be
Correct Answer
C. 1/2 inch from the bottom of the glass
Explanation
The proper level of the gauge of the hydraulic reservoir should be 1/2 inch from the bottom of the glass. This ensures that there is enough hydraulic fluid in the reservoir to properly lubricate and cool the system, while also allowing for expansion and contraction of the fluid as needed. Having the fluid level too high or too low can lead to inefficient operation or damage to the hydraulic system.
42.
During an operational check of a SGNSC you find that the engine starts, is running at 3,000 rpm, but the nitrogen purity does not reach 95.5% within 30 minutes. What is the probable cause of this malfunction?
Correct Answer
A. Warming door is not lowered for cold weather operating conditions
Explanation
The probable cause of the malfunction is that the warming door is not lowered for cold weather operating conditions. This could prevent the engine from reaching the required nitrogen purity within 30 minutes.
43.
What is important to keep in mind when performing maintenance on the SGNSC?
Correct Answer
D. Safety
Explanation
When performing maintenance on the SGNSC, safety is important to keep in mind. This means taking necessary precautions to ensure the well-being and protection of individuals involved in the maintenance process. Safety measures may include wearing appropriate personal protective equipment, following proper procedures, and being aware of potential hazards. By prioritizing safety, the risk of accidents or injuries can be minimized, creating a safer working environment for everyone involved.
44.
When filling and bleeding the hydraulic system of the MJ-2A-1 hydraulic test stand, the reservoir selector valve must be in the
Correct Answer
C. Aircraft position
Explanation
When filling and bleeding the hydraulic system of the MJ-2A-1 hydraulic test stand, the reservoir selector valve must be in the aircraft position. This is because the aircraft position allows the hydraulic fluid to flow directly from the aircraft's hydraulic system into the test stand's reservoir. This ensures that the test stand is filled with the same type of hydraulic fluid that is used in the aircraft, which is necessary for accurate testing and troubleshooting of the hydraulic system.
45.
The purpose of the low pressure pump on the MJ-2A-1 is to ensure a constant flow of fluid to the
Correct Answer
D. High pressure filters
Explanation
The low pressure pump on the MJ-2A-1 is designed to maintain a consistent flow of fluid to the high pressure filters. These filters are responsible for removing any contaminants or impurities from the fluid before it reaches the aircraft pumps. By ensuring a constant flow of fluid to the high pressure filters, the low pressure pump helps to maintain the efficiency and effectiveness of the filtration system, thereby protecting the aircraft pumps from potential damage or malfunction caused by contaminated fluid.
46.
In the MJ-2A-1 hydraulic test stand, the output volume of the high pressure pump is controlled by the
Correct Answer
A. Volume control
Explanation
The correct answer is volume control. In the MJ-2A-1 hydraulic test stand, the output volume of the high pressure pump is controlled by the volume control. This means that the volume of hydraulic fluid being pumped by the high pressure pump can be adjusted and regulated using the volume control mechanism. This allows for precise control over the output volume of the pump, ensuring that the desired amount of hydraulic fluid is being delivered for the intended application.
47.
If the position of the reservoir selector valve is changed in the hydraulic test stand during operation, the operator may cause the
Correct Answer
A. Flowmeter to be damaged
Explanation
If the position of the reservoir selector valve is changed in the hydraulic test stand during operation, it can cause a sudden change in the flow direction and pressure of the hydraulic fluid. This sudden change can lead to excessive pressure or turbulence within the flowmeter, causing it to be damaged.
48.
What engine system safety device on the MJ-2A-1 hydraulic test stand sounds the warning horn in the event of an engine system malfunction?
Correct Answer
B. Oil pressure switch
Explanation
The oil pressure switch is responsible for monitoring the oil pressure in the engine system. In the event of an engine system malfunction where the oil pressure drops below a certain level, the oil pressure switch will activate the warning horn to alert the operator. This is an important safety feature as low oil pressure can indicate potential engine damage or failure, and immediate action may be required to prevent further damage or accidents.
49.
When setting the controls for operation of the MJ-2A-1 hydraulic test stand, what control must you set in the OPEN position?
Correct Answer
B. Return system bypass valve
Explanation
In order to operate the MJ-2A-1 hydraulic test stand, the control that must be set in the OPEN position is the return system bypass valve. This valve allows the hydraulic fluid to bypass the system and return to the reservoir, preventing excessive pressure build-up. By opening this valve, the hydraulic system can function properly and maintain the desired pressure levels during operation.
50.
When filling and bleeding the MJ-2A-1 hydraulic test stand, the system should be pressurized and bled until
Correct Answer
A. A solid line of fluid can be seen in the sight tube
Explanation
When filling and bleeding the hydraulic test stand, the system should be pressurized and bled until a solid line of fluid can be seen in the sight tube. This indicates that there are no air bubbles present in the system and the hydraulic fluid is filling the sight tube completely. This ensures that the system is properly pressurized and bled, ready for operation.