# 2A656 Vol 3 Ure (2013)

Approved & Edited by ProProfs Editorial Team
The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.
Learn about Our Editorial Process
| By Roach187fw
R
Roach187fw
Community Contributor
Quizzes Created: 5 | Total Attempts: 3,550
Questions: 72 | Attempts: 842

Settings

• 1.

### (401) The constant speed drive (CSD) that is used to drive a 60/80 kilovolts amperes (kVA) generator has an output of approximately

• A.

4,000 revolutions per minute (rpm).

• B.

6,000 rpm.

• C.

8,000 rpm.

• D.

10,000 rpm.

C. 8,000 rpm.
Explanation
The correct answer is 8,000 rpm. A constant speed drive (CSD) is used to drive a generator with a power output of 60/80 kVA. The generator's output is directly related to the speed at which it operates. Since the CSD is designed to maintain a constant speed, it can be inferred that the generator operates at a speed of 8,000 rpm.

Rate this question:

• 2.

### (401) In an alternating current (AC) power supply system, which component controls load division during parallel generator operation?Type question here

• A.

• B.

Underspeed switch.

• C.

Constant speed drive.

• D.

Generator control unit.

Explanation
The load controller is responsible for controlling load division during parallel generator operation in an AC power supply system. It ensures that the load is evenly distributed among the generators, preventing overloading of any one generator. This helps to maintain the stability and efficiency of the system.

Rate this question:

• 3.

### (401) The undervoltage activation point for the main generator in a volts alternating current (VAC) power supply system is

• A.

93 [±3] VAC.

• B.

103 [±3] VAC.

• C.

115 [±2] VAC.

• D.

125 [±2] VAC.

B. 103 [±3] VAC.
Explanation
The correct answer is 103 [±3] VAC. This means that the undervoltage activation point for the main generator in a VAC power supply system is 103 volts with a tolerance of ±3 volts. This indicates that if the voltage drops below 100 volts or rises above 106 volts, the undervoltage protection will be activated and take necessary actions to prevent damage to the system.

Rate this question:

• 4.

### (401) At what volts alternating current (VAC) range does the generator control unit (GCU) in an AC power supply system maintain generator output?

• A.

135 [±3] VAC.

• B.

125 [±3] VAC.

• C.

115 [±2] VAC.

• D.

105 [±2] VAC.

C. 115 [±2] VAC.
Explanation
The generator control unit (GCU) in an AC power supply system maintains the generator output at 115 [±2] VAC. This means that the GCU is designed to regulate the voltage output of the generator within a range of 113 to 117 VAC, with a tolerance of ±2 volts. This ensures that the generator produces a stable and consistent voltage output within this specified range, which is suitable for powering electrical devices and equipment in the AC power supply system.

Rate this question:

• 5.

### (401) In an alternating current (AC) power supply system, what component connects the 115/200 volts alternating current (VAC) main generator output to the main power buses?

• A.

Bus tie lockout (BTL).

• B.

Bus tie contactor (BTC).

• C.

Generator control unit (GCU).

• D.

Generator line contactor (GLC).

D. Generator line contactor (GLC).
Explanation
The correct answer is Generator line contactor (GLC). In an AC power supply system, the GLC connects the 115/200 volts AC main generator output to the main power buses. The GLC is responsible for controlling the flow of electricity from the generator to the power buses, allowing the power to be distributed to the various electrical loads in the system. The GLC is an important component in ensuring the proper functioning and distribution of power in an AC power supply system.

Rate this question:

• 6.

### (402) Which emergency alternating current (AC) power system component connects the output of the emergency generator to the essential bus?

• A.

Emergency power disconnect relay (EPDR).

• B.

Emergency power interlock relay (EPIR).

• C.

Emergency generator test switch (EGTS).

• D.

Power fail relay (PFR).

A. Emergency power disconnect relay (EPDR).
Explanation
The emergency power disconnect relay (EPDR) is the component that connects the output of the emergency generator to the essential bus. This relay is responsible for ensuring that the emergency power is properly distributed to the essential systems in case of a power failure. It acts as a switch, connecting the generator output to the essential bus when needed and disconnecting it when not needed. This ensures that the essential systems receive power from the generator when necessary, providing a reliable source of electricity during emergencies.

Rate this question:

• 7.

### (402) Which emergency alternating current (AC) power system component prevents the emergency generator from dropping off-line when the aircraft lands?

• A.

Emergency power disconnect relay (EPDR).

• B.

Emergency power interlock relay (EPIR).

• C.

Emergency generator test switch (EGTS).

• D.

Power fail relay (PFR).

B. Emergency power interlock relay (EPIR).
Explanation
The emergency power interlock relay (EPIR) is the component that prevents the emergency generator from dropping off-line when the aircraft lands. This relay is responsible for maintaining the connection between the generator and the aircraft's electrical system, ensuring a continuous power supply even during landing. It acts as a safety measure to prevent any interruptions in power during critical moments.

Rate this question:

• 8.

### (402) What is the minimum volts alternating current (VAC) requirement to energize the emergency power disconnect relay (EPDR)?

• A.

90 VAC from A phase.

• B.

90 VAC from C phase.

• C.

93 VAC from A phase.

• D.

93 VAC from C phase.

D. 93 VAC from C phase.
Explanation
The minimum volts alternating current (VAC) requirement to energize the emergency power disconnect relay (EPDR) is 93 VAC from the C phase. This means that in order to activate the EPDR, a minimum voltage of 93 VAC needs to be supplied from the C phase of the alternating current source.

Rate this question:

• 9.

### (403) What external power system component disconnects external power from the aircraft?

• A.

Bus protection panel (BPP).

• B.

Auxiliary power unit (APU).

• C.

APU/external power contactor (AEPC).

• D.

APU/external power disconnect contactor (AEDC).

D. APU/external power disconnect contactor (AEDC).
Explanation
The external power system component that disconnects external power from the aircraft is the APU/external power disconnect contactor (AEDC). This component is responsible for isolating the aircraft from the external power source, ensuring that there is no electrical connection between the aircraft and the external power supply. By disconnecting the external power, the AEDC helps to prevent any potential electrical issues or damage to the aircraft's electrical system.

Rate this question:

• 10.

### (403) The auxiliary source selected to power the tie bus in the auxiliary power unit (APU) is determined by the

• A.

Lockout relay (LOR).

• B.

Bus protection panel (BPP).

• C.

APU/external power contactor (AEPC).

• D.

APU external power disconnect contactor (AEDC).

C. APU/external power contactor (AEPC).
Explanation
The correct answer is APU/external power contactor (AEPC). The auxiliary source selected to power the tie bus in the auxiliary power unit (APU) is determined by the APU/external power contactor (AEPC). This means that either the APU or an external power source can be used to power the tie bus, depending on the position of the AEPC. The lockout relay (LOR) is not responsible for determining the power source for the tie bus. The bus protection panel (BPP) and APU external power disconnect contactor (AEDC) are not mentioned in relation to selecting the power source for the tie bus.

Rate this question:

• 11.

### (403) What relays connect the auxiliary power source to the aircraft buses?

• A.

Bus tie connector (BTC).

• B.

Bus protection panel (BPP).

• C.

APU/external power contactor (AEPC).

• D.

APU/external power disconnect contactor (AEDC).

A. Bus tie connector (BTC).
Explanation
The bus tie connector (BTC) is responsible for connecting the auxiliary power source to the aircraft buses. It serves as a relay that allows power to flow between different electrical systems on the aircraft. The BTC ensures that power is distributed properly and that the aircraft's electrical systems can operate efficiently.

Rate this question:

• 12.

### (404) During which troubleshooting step do you review the Air Force Technical Order (AFTO) Form 781A?

• A.

Learn normal system operation.

• B.

Define the discrepancy.

• C.

Limit the malfunction.

• D.

B. Define the discrepancy.
Explanation
During the troubleshooting process, reviewing the Air Force Technical Order (AFTO) Form 781A is done in order to define the discrepancy. This form contains information about the specific problem or issue that needs to be addressed. By reviewing this form, technicians can gather relevant details and specifications related to the discrepancy, which helps them in identifying the root cause and developing an appropriate solution. This step is crucial in effectively troubleshooting and resolving the problem.

Rate this question:

• 13.

### (405) The transformer rectifier units in a volts direct current (VDC) power system convert three-phase 115 volts alternating current (VAC) into

• A.

10 to 12 VDC.

• B.

26 to 31 VDC.

• C.

32 to 36 VDC.

• D.

52 to 56 VDC.

B. 26 to 31 VDC.
Explanation
The transformer rectifier units in a VDC power system convert three-phase 115 VAC into 26 to 31 VDC.

Rate this question:

• 14.

### (405) In the direct current (DC) power supply system, the delta-wound secondaries of the internal transformer in the transformer rectifier (TR) unit are used to provide a more stable

• A.

Current input.

• B.

Voltage input.

• C.

Current output.

• D.

Voltage output.

C. Current output.
Explanation
The delta-wound secondaries of the internal transformer in the transformer rectifier (TR) unit are used to provide a more stable current output. This means that the current output will be constant and not fluctuate, ensuring a steady supply of current to the system.

Rate this question:

• 15.

### (405) In the direct current (DC) power supply system, the reverse current relays (RCR) deenergize when the potential at the

• A.

GEN terminal is greater than the indicator terminal.

• B.

GEN terminal is less than the battery terminal.

• C.

GEN terminal is greater than the SW terminal.

• D.

BAT terminal is less than the SW terminal.

B. GEN terminal is less than the battery terminal.
Explanation
The reverse current relays (RCR) in a direct current (DC) power supply system are designed to deenergize when the potential at the GEN terminal is less than the battery terminal. This means that if the potential at the GEN terminal drops below the potential at the battery terminal, the RCR will deenergize. This is an important safety feature to prevent reverse current flow and protect the system from damage.

Rate this question:

• 16.

### (406) If the normal battery is supplying direct current (DC) to the battery bus and emergency DC bus, your first step in troubleshooting is to

• A.

Define the problem.

• B.

• C.

Know system operation.

• D.

Perform an operational check.

C. Know system operation.
Explanation
Knowing the system operation is the first step in troubleshooting when the normal battery is supplying direct current (DC) to the battery bus and emergency DC bus. This is because understanding how the system is supposed to work will help identify any deviations or abnormalities. By knowing the system operation, one can compare it to the actual behavior and determine if there is a problem. Taking meter readings and performing an operational check can come later in the troubleshooting process once the problem is identified.

Rate this question:

• 17.

### (406) If the normal battery will not charge but the standby battery is OK, then you start taking meter readings at the

• A.

No. 1 transformer rectifier (TR).

• B.

No. 2 TR.

• C.

Standby battery relay.

• D.

Normal battery relay.

D. Normal battery relay.
Explanation
If the normal battery is not charging but the standby battery is fine, it indicates that there may be an issue with the normal battery relay. The normal battery relay is responsible for allowing the flow of current to the normal battery for charging. If this relay is faulty or not functioning properly, it could prevent the normal battery from charging. Therefore, it is necessary to start taking meter readings at the normal battery relay to diagnose and troubleshoot the problem.

Rate this question:

• 18.

### (407) Which flight control system operates the disconnect clutch in the stabilizer trim actuator assembly?

• A.

Manual system.

• B.

Autopilot system.

• C.

Hydraulic system.

• D.

Electric power system.

A. Manual system.
Explanation
The manual system operates the disconnect clutch in the stabilizer trim actuator assembly. This means that the disconnect clutch can be disengaged and the stabilizer trim actuator can be manually controlled by the pilot. The other options, such as the autopilot system, hydraulic system, and electric power system, do not directly operate the disconnect clutch in the stabilizer trim actuator assembly.

Rate this question:

• 19.

### (408) The aircraft write-up states that the leading edge of the stabilizer does not move down when either horizontal stabilizer trim control switch is put to the NOSE UP position. Where is the best place to start taking meter readings?

• A.

Check for 28 VDC between pins A and H, B and H, and G and H of the actuator connector plug.

• B.

Check for 115 VAC between pins A and H, B and H, and G and H of the actuator connector plug.

• C.

Check for 28 VDC at the up-limit switch with either of the horizontal stabilizer trim control switches actuated.

• D.

Check for 28 VDC at pin F of the actuator connector plug with either of the horizontal stabilizer trim control switches actuated.

D. Check for 28 VDC at pin F of the actuator connector plug with either of the horizontal stabilizer trim control switches actuated.
Explanation
The correct answer is to check for 28 VDC at pin F of the actuator connector plug with either of the horizontal stabilizer trim control switches actuated. This is the best place to start taking meter readings because it directly tests the voltage at the actuator connector plug, which is where the issue with the stabilizer not moving down is likely to be located. By checking for 28 VDC at pin F, it can be determined if there is a problem with the voltage supply to the actuator, which could be causing the issue with the stabilizer.

Rate this question:

• 20.

### (409) Which component is used as an emergency means of controlling the aileron trim control circuit?

• A.

Control stick grip trim switch.

• B.

Aileron trim control switch.

• C.

Trim selector switch.

• D.

Auxiliary trim switch.

D. Auxiliary trim switch.
Explanation
The auxiliary trim switch is used as an emergency means of controlling the aileron trim control circuit. It acts as a backup switch in case the primary trim switches fail or become inoperable. This switch allows the pilot to manually adjust the aileron trim in case of any emergency or malfunction.

Rate this question:

• 21.

### (409) When the stick grip trim selector switch is moved to the left, the position of the aircraft left aileron is

• A.

Up (left wing up).

• B.

Up (left wing down).

• C.

Down (right wing up).

• D.

Down (right wing down).

B. Up (left wing down).
Explanation
When the stick grip trim selector switch is moved to the left, it causes the left aileron of the aircraft to move in the downward direction. This downward movement of the left aileron creates more lift on the left wing, causing it to move down. Therefore, the correct answer is "up (left wing down)."

Rate this question:

• 22.

### (410) After you release the stick grip trim selector switch, the trim indicator light

• A.

Extinguishes.

• B.

Remains illuminated.

• C.

Flashes on and off briefly.

• D.

Remains on throughout the full cycle of the ailerons.

A. Extinguishes.
Explanation
After releasing the stick grip trim selector switch, the trim indicator light extinguishes. This indicates that the trim adjustment has been completed and the aircraft is now in a stable trim position.

Rate this question:

• 23.

### (410) Before operating the aileron trim system, you must supply power to

• A.

Both the electrical and hydraulic systems.

• B.

The electrical system.

• C.

The hydraulic system.

• D.

The bleed air system.

A. Both the electrical and hydraulic systems.
Explanation
Before operating the aileron trim system, it is necessary to supply power to both the electrical and hydraulic systems. This is because the aileron trim system requires electrical power to operate the trim motor, which adjusts the position of the ailerons. Additionally, hydraulic power is needed to supply the necessary pressure to move the ailerons. Therefore, both systems must be powered in order for the aileron trim system to function correctly.

Rate this question:

• 24.

### (410) When you achieve maximum aileron travel, you should see the aileron takeoff trim indicator lights

• A.

Change from red to green.

• B.

Turn on.

• C.

Go out.

• D.

Flash.

D. Flash.
Explanation
When you achieve maximum aileron travel, the aileron takeoff trim indicator lights flash. This indicates that the ailerons have reached their maximum deflection and are now in the correct position for takeoff. The flashing lights serve as a visual confirmation for the pilot that the ailerons are properly set and ready for flight.

Rate this question:

• 25.

### (411) The slotted wing flaps are used on heavy aircraft and

• A.

Extended forward and downward.

• B.

Form a slot between the flap and the wing.

• C.

Increases the chamber or curvature of the wing.

• D.

Lowers the trailing edge to about 40° below its retracted (UP) position.

B. Form a slot between the flap and the wing.
Explanation
Slotted wing flaps are used on heavy aircraft to form a slot between the flap and the wing. This slot allows high-energy air from below the wing to flow over the top surface, delaying the separation of airflow and increasing lift. By creating a slot, the flaps increase the chamber or curvature of the wing, which further enhances lift generation. This design also lowers the trailing edge of the wing, creating a downward angle that helps to increase lift and improve aircraft performance.

Rate this question:

• 26.

### (412) The three positions for the speedbrake switch are

• A.

Open, hold, and land.

• B.

Open, hold, and retract.

• C.

Open, release, and retract.

• D.

Actuate, hold, and retract.

B. Open, hold, and retract.
Explanation
The correct answer is open, hold, and retract. The speedbrake switch on an aircraft has three positions. The open position allows the speedbrake to deploy fully, increasing drag and slowing down the aircraft. The hold position keeps the speedbrake in its current position, maintaining the desired level of drag. The retract position stows the speedbrake back into its original position, reducing drag and allowing the aircraft to resume normal flight.

Rate this question:

• 27.

### (413) After replacing the 43° position switch on the speedbrake system, your next and final step is to

• A.

Ohms check the switch.

• B.

Voltage check the switch.

• C.

Perform an operational check.

• D.

Turn in all tools and test equipment.

C. Perform an operational check.
Explanation
After replacing the 43° position switch on the speedbrake system, the next and final step is to perform an operational check. This is necessary to ensure that the switch is functioning correctly and that the speedbrake system is working as intended. It is important to test the switch in an operational setting to verify its functionality and to make sure that the replacement has been successful. This step helps to ensure the safety and proper functioning of the speedbrake system.

Rate this question:

• 28.

### (414) The operation of the air compressor in an engine fuel-air starter system is controlled by

• A.

The ground crew.

• B.

A pressure switch.

• C.

A centrifugal switch.

• D.

The pilot using an on-and-off switch.

B. A pressure switch.
Explanation
The operation of the air compressor in an engine fuel-air starter system is controlled by a pressure switch. A pressure switch is a device that monitors the pressure in a system and activates or deactivates a circuit based on the predetermined pressure level. In this case, the pressure switch is responsible for controlling the operation of the air compressor, which is used to start the engine. When the pressure in the system reaches the desired level, the pressure switch will activate the compressor, and when the pressure drops below a certain threshold, the pressure switch will deactivate the compressor.

Rate this question:

• 29.

### (414) When a pneumatic starter reaches maximum speed, the ground circuit to the starter relay is opened by

• A.

The pilot valve.

• B.

A pressure switch.

• C.

Centrifugal switch.

• D.

The ON-OFF switch in the cockpit.

C. Centrifugal switch.
Explanation
The correct answer is centrifugal switch. When a pneumatic starter reaches maximum speed, the centrifugal switch opens the ground circuit to the starter relay. This switch is designed to automatically disconnect the starter motor from the power source once the motor reaches a certain speed. This helps to prevent damage to the starter motor and allows it to disengage once it is no longer needed.

Rate this question:

• 30.

### (415) The volts alternating current (VAC) power requirement for operation of an AC ignition system is

• A.

115 VAC, 60 hertz.

• B.

208 VAC, 60 hertz.

• C.

115 VAC, 400 hertz.

• D.

208 VAC, 400 hertz.

C. 115 VAC, 400 hertz.
• 31.

### (415) Once the voltage goes through the transformer in the direct current (DC) ignition system, it is then applied to the

• A.

Igniter plug.

• B.

Vibrator unit.

• C.

Small generator.

• D.

Step-up transformer.

A. Igniter plug.
Explanation
In a direct current (DC) ignition system, the voltage is first passed through a transformer. After going through the transformer, the voltage is applied to the igniter plug. This means that the igniter plug is the component that receives the voltage and initiates the ignition process. The other options, vibrator unit, small generator, and step-up transformer, are not directly involved in the ignition process and do not receive the voltage from the transformer.

Rate this question:

• 32.

### (415) The engine ignition circuit for the B model of C–135 aircraft does not contain

• A.

A throttle switch.

• B.

Two ignition units.

• C.

Two spark igniters.

• D.

An ignition control-and-start switch.

A. A throttle switch.
Explanation
The engine ignition circuit for the B model of C-135 aircraft does not contain a throttle switch. The throttle switch is not a part of the ignition circuit, but rather a component of the fuel system. The ignition circuit is responsible for providing the spark necessary for combustion in the engine, and it consists of two ignition units and two spark igniters. However, the throttle switch is not involved in the ignition process and is not present in the ignition circuit.

Rate this question:

• 33.

### (416) The gas turbine compressor (GTC) is stopped manually by turning the control switch to OFF or by pulling the GTC fire emergency handle and causing the

• A.

Fuel control relay to de-energize.

• B.

Fuel control relay to energize.

• C.

GTC fuel relay to de-energize.

• D.

GTC fuel relay to energize.

A. Fuel control relay to de-energize.
Explanation
When the gas turbine compressor (GTC) needs to be stopped, it can be done manually by turning the control switch to OFF or by pulling the GTC fire emergency handle. This action causes the fuel control relay to de-energize, meaning that it stops receiving power. This de-energizing of the fuel control relay results in the GTC fuel relay also being de-energized, which ultimately stops the flow of fuel to the GTC and shuts it down.

Rate this question:

• 34.

### (417) What is the last thing you must do before completing a troubleshooting cycle?

• A.

Repair the defective item.

• B.

Bench-check any new parts.

• C.

Perform an operational check.

• D.

Replace any malfunctioning part.

C. Perform an operational check.
Explanation
Before completing a troubleshooting cycle, the last thing you must do is perform an operational check. This is important to ensure that the issue has been resolved and that the system or equipment is functioning properly. By conducting an operational check, you can verify that the troubleshooting steps taken have been effective and that the problem has been successfully resolved. This step helps to prevent any further issues or malfunctions and ensures that the equipment is ready for use.

Rate this question:

• 35.

### (418) What type of fuel system valves link the left wing and aft body tanks to the right wing, mid body, and forward body tanks?

• A.

Crossfeed.

• B.

Fire shutoff.

• C.

Interconnect.

• D.

Fuel-level control.

C. Interconnect.
Explanation
The correct answer is Interconnect. Interconnect valves are fuel system valves that link the left wing and aft body tanks to the right wing, mid body, and forward body tanks. These valves allow fuel to be transferred between tanks to maintain balance and ensure a steady fuel supply to the engines.

Rate this question:

• 36.

### (418) How does the auxiliary fuel tank indicating system give a no-flow indication?

• A.

• B.

Flashing red light.

• C.

• D.

Flashing amber light.

D. Flashing amber light.
Explanation
The auxiliary fuel tank indicating system gives a no-flow indication through a flashing amber light. This means that there is a problem with the fuel flow in the auxiliary tank. A steady red light typically indicates a more serious issue, such as a complete failure, while a flashing amber light suggests a partial or intermittent problem with the fuel flow.

Rate this question:

• 37.

### (419) How many boost pumps are there in main fuel tank No. 1?

• A.

Two.

• B.

Three.

• C.

Four.

• D.

Five.

C. Four.
Explanation
There are four boost pumps in main fuel tank No. 1.

Rate this question:

• 38.

### (419) The output in gallons per minute (gpm) of the scavenge pumps is approximately

• A.

½ gpm.

• B.

1 gpm.

• C.

2 gpm.

• D.

3 gpm.

C. 2 gpm.
Explanation
The scavenge pumps have an output of approximately 2 gallons per minute (gpm).

Rate this question:

• 39.

### (420) To begin troubleshooting a fuel pump inoperative writeup; you would know the system, and then

• A.

Perform an operational check.

• B.

Limit the malfunction.

• C.

• D.

Replace a bad pump.

A. Perform an operational check.
Explanation
Performing an operational check is the logical next step in troubleshooting a fuel pump that is not working. By conducting this check, one can determine if the fuel pump is receiving power and if it is functioning properly. This step helps to narrow down the possible causes of the issue and can guide further troubleshooting actions. It is a crucial step in the process of identifying and resolving the problem with the fuel pump.

Rate this question:

• 40.

### (421) Thermal switches in a fire-warning system are normally connected in

• A.

Series with each other.

• B.

Series with the power source and with the warning light.

• C.

Parallel with the power source and in series with each other.

• D.

Parallel with each other and in series with the warning light.

D. Parallel with each other and in series with the warning light.
Explanation
Thermal switches in a fire-warning system are connected in parallel with each other to ensure that if one switch is triggered, it does not affect the operation of the other switches. However, they are also connected in series with the warning light to ensure that if any of the switches are triggered, the warning light is activated. This configuration allows for multiple switches to detect a fire and activate the warning light simultaneously.

Rate this question:

• 41.

### (421) Frequently used in fire warning systems, the fire detector that has a high-nickel steel rod located along the centerline of a stainless steel tube assembly is called

• A.

A photoconductive cell.

• B.

An iron fireman switch.

• C.

A FENWAL® switch.

• D.

A continuous cable.

B. An iron fireman switch.
Explanation
The correct answer is an iron fireman switch. This type of fire detector is frequently used in fire warning systems and consists of a high-nickel steel rod located along the centerline of a stainless steel tube assembly. The iron fireman switch is designed to detect the presence of fire or heat and activate the appropriate alarm or suppression system.

Rate this question:

• 42.

### (421) The maximum circuit resistance within a thermocouple circuit is

• A.

Infinity.

• B.

5 ohms.

• C.

50 ohms.

• D.

500 ohms.

B. 5 ohms.
Explanation
The maximum circuit resistance within a thermocouple circuit is 5 ohms. This is because the resistance in the circuit should be kept as low as possible in order to minimize errors in temperature measurement. A higher circuit resistance can introduce additional resistance and lead to inaccuracies in the voltage generated by the thermocouple. Therefore, it is important to keep the circuit resistance below 5 ohms to ensure accurate temperature readings.

Rate this question:

• 43.

### (421) Amplifiers used in the photoelectric fire detector system are sensitive only to

• A.

Sunlight.

• B.

Light emitted from flashlights.

• C.

Signals with a frequency between 7 and 60 Hz.

• D.

Signals with a frequency between 60 and 160 Hz.

C. Signals with a frequency between 7 and 60 Hz.
Explanation
The amplifiers used in the photoelectric fire detector system are designed to be sensitive to signals with a frequency between 7 and 60 Hz. This frequency range is specifically chosen because it corresponds to the flickering frequency of a flame. By being sensitive to this frequency range, the amplifier can effectively detect the presence of a flame and trigger the fire alarm system.

Rate this question:

• 44.

### (421) The direct current (DC) voltage that is supplied to the lights in a photoelectric circuit is pulsed at a rate of

• A.

10 hertz (Hz).

• B.

100 Hz.

• C.

200 Hz

• D.

400 Hz.

A. 10 hertz (Hz).
Explanation
The correct answer is 10 hertz (Hz). In a photoelectric circuit, the direct current (DC) voltage supplied to the lights is pulsed at a rate of 10 hertz. This means that the voltage is being turned on and off 10 times per second. This pulsing of the voltage allows for precise control of the lights and is commonly used in applications such as photography or sensing systems.

Rate this question:

• 45.

### (421) In a continuous loop fire detection system, the shield of the continuous loop is constructed of

• A.

Soft iron.

• B.

Aluminum.

• C.

Malleable tin.

• D.

INCONEL®.

D. INCONEL®.
Explanation
INCONEL® is the correct answer for the construction of the shield in a continuous loop fire detection system. INCONEL® is a type of nickel-chromium alloy known for its high resistance to heat and corrosion. This makes it an ideal material for use in fire detection systems as it can withstand high temperatures and protect the continuous loop from damage. Soft iron, aluminum, and malleable tin do not possess the same level of heat and corrosion resistance as INCONEL®, making them less suitable for this purpose.

Rate this question:

• 46.

### (422) For the master caution lamps in a master caution system to illuminate,

• A.

Transistor Q1 must remain at the CUTOFF position.

• B.

Transistor Q2 must remain at the CUTOFF position.

• C.

Controlled rectifier SCR2 must forward bias transistor Q2.

• D.

Controlled rectifier SCR2 conducts current to forward bias transistor Q1.

D. Controlled rectifier SCR2 conducts current to forward bias transistor Q1.
Explanation
In a master caution system, the master caution lamps illuminate when controlled rectifier SCR2 conducts current to forward bias transistor Q1. This means that the current flows through SCR2, which then allows current to flow through Q1, causing the lamps to light up.

Rate this question:

• 47.

### (422) When a fault occurs, the individual caution lamps in the master caution system remain on until

• A.

The shutter closes.

• B.

The fault is corrected.

• C.

The reset circuit is energized.

• D.

Another system fault is detected.

B. The fault is corrected.
Explanation
When a fault occurs, the individual caution lamps in the master caution system remain on until the fault is corrected. This means that once a fault is detected, the caution lamps will continue to stay on until the issue causing the fault is resolved. The lamps serve as a visual indication to the operator that there is a problem, and they will only turn off once the fault has been fixed.

Rate this question:

• 48.

### (423) When the cargo and personnel doors close and lock, the door

• A.

Open relay will energize.

• B.

Open relay will de-energize.

• C.

Position relay will energize.

• D.

Position relay will de-energize.

B. Open relay will de-energize.
Explanation
When the cargo and personnel doors close and lock, it indicates that the doors are secure and in the closed position. In this case, the open relay, which is responsible for opening the doors, will de-energize or turn off. This is because there is no need for the doors to remain open once they are closed and locked.

Rate this question:

• 49.

### (423) When all systems are configured for flight, the pilot or copilot must press the

• A.

Aileron roll trim lever.

• B.

Autopilot engage lever.

• C.

Hydraulic pitch trim levers.

• D.

Thrust reverser locked lever.

C. Hydraulic pitch trim levers.
Explanation
The correct answer is hydraulic pitch trim levers. When all systems are configured for flight, the pilot or copilot must press the hydraulic pitch trim levers. This is because the hydraulic pitch trim system is responsible for adjusting the aircraft's pitch attitude and maintaining the desired flight path. By pressing the hydraulic pitch trim levers, the pilot or copilot can make necessary adjustments to the aircraft's pitch trim, ensuring stable and controlled flight. The other options, such as the aileron roll trim lever, autopilot engage lever, and thrust reverser locked lever, are not relevant to the process of configuring systems for flight.

Rate this question:

• 50.

### (424) You determine the bulbs are good and the circuit breakers are working for a typical take-off warning system problem; you then check for 28 volts direct current (VDC) at the sockets of the take-off lights and you do not find voltage. Where is the next place you should check?

• A.

Spoiler controls take-off warning relay contacts.

• B.

Hydraulic system No. 3 relay contacts.

• C.

Stabilizer trim relay contacts.

• D.

Touchdown relay contact.

A. Spoiler controls take-off warning relay contacts.
Explanation
The next place you should check is the spoiler controls take-off warning relay contacts. This is because the take-off warning system is controlled by the relay contacts in the spoiler controls. If there is no voltage at the sockets of the take-off lights, it suggests that there may be an issue with the relay contacts in the spoiler controls, which are responsible for supplying power to the lights. Checking these contacts would be the logical next step in troubleshooting the problem.

Rate this question:

Related Topics