2A533A Vol.3 Part 2

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    HAVE QUICK radios resist jamming by

    • Frequency hopping
    • Retransmission
    • Phase shifting
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About This Quiz

Explore the fundamentals of pulse-modulation radar systems in '2a533a vol. 3 part 2'. This quiz assesses knowledge on key components like antennas and power supplies, the concept of pulse repetition frequency, and the application of the Doppler principle in radar technology.

Radar Systems Quizzes & Trivia

Quiz Preview

  • 2. 

    Which component in a pulse-modulation radar set provides the voltages that operate the other radar components?

    • Antenna

    • Transmitter

    • Power supply

    Correct Answer
    A. Power supply
    Explanation
    The power supply in a pulse-modulation radar set provides the necessary voltages to operate the other radar components. It supplies the required electrical power to the antenna and transmitter, enabling them to function properly. Without a functioning power supply, the other components would not receive the necessary voltages to operate, resulting in the radar set not being able to function effectively.

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  • 3. 

    Which radar application is used to produce a pictorial map of the terrain?

    • Ground mapping

    • Terrain-following

    • Terrain avoidance

    Correct Answer
    A. Ground mapping
    Explanation
    Ground mapping is the radar application used to produce a pictorial map of the terrain. This involves using radar technology to collect data about the surface of the Earth and create a visual representation of the terrain. By analyzing the radar echoes and reflections, ground mapping radar can provide detailed information about the topography, vegetation, and other features of the terrain. This information is valuable for various purposes, such as military operations, navigation, and environmental monitoring.

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  • 4. 

    In a frequency-shift radar system, what is the relationship between a transmitter/receiver and an aircraft when the received frequency is lower than the transmitted frequency?

    • The aircraft is not reflecting any of the RDR pulses

    • The aircraft is flying towards the RT

    • The aircraft is flying away from the RT

    Correct Answer
    A. The aircraft is flying away from the RT
    Explanation
    When the received frequency is lower than the transmitted frequency in a frequency-shift radar system, it indicates that the aircraft is flying away from the radar transmitter (RT). This is because the frequency shift occurs due to the Doppler effect, where the frequency of the signal changes based on the relative motion between the transmitter/receiver and the aircraft. A lower received frequency suggests that the aircraft is moving away from the radar, causing a decrease in the frequency of the reflected signal.

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  • 5. 

    In a pulse-modulation radar system. the pulse repetition frequency is the number of pulses

    • That are received within 1 second

    • That are transmitted within 1 second

    • That strike the target within 1 second

    Correct Answer
    A. That are transmitted within 1 second
    Explanation
    The pulse repetition frequency in a pulse-modulation radar system refers to the number of pulses that are transmitted within 1 second. This means that it measures how frequently the radar system sends out pulses of electromagnetic energy. By knowing the pulse repetition frequency, the radar system can determine the range and velocity of the target being detected.

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  • 6. 

    Ultra-high frequency radios are primarily used for

    • Long-range communication

    • Direction-finding operations

    • Line-of-sight communications

    Correct Answer
    A. Line-of-sight communications
    Explanation
    Ultra-high frequency radios are primarily used for line-of-sight communications. This means that they are most effective when there is a direct, unobstructed path between the transmitting and receiving antennas. UHF signals do not penetrate obstacles like buildings or mountains as well as lower frequency signals, so they are ideal for short-range communication over relatively flat terrain. This makes them suitable for applications such as walkie-talkies, mobile phones, and wireless local area networks (WLANs).

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  • 7. 

    The part of the radar sets low observable antenna that is addressed to steer the radio-frequency beam is the

    • Phase control modules

    • Radio-frequency roll resolver

    • Radio-frequency quadrant manifolds

    Correct Answer
    A. Phase control modules
    Explanation
    The correct answer is phase control modules. Phase control modules are responsible for steering the radio-frequency beam in radar systems. They help in adjusting the phase of the radio waves emitted by the antenna, which determines the direction in which the beam is steered. By controlling the phase, the radar system can scan and track targets effectively. Radio-frequency roll resolver and radio-frequency quadrant manifolds are not directly related to steering the beam, making them incorrect options.

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  • 8. 

    The voltage standing-wave ration is determined by comparing the radars's

    • Reflected power to the TX power

    • Reflected power to the receiver's sensitivity

    • Transmitter power to the receiver's sensitivity

    Correct Answer
    A. Reflected power to the TX power
    Explanation
    The voltage standing-wave ratio (VSWR) is a measure of how efficiently power is transferred from the transmitter to the antenna. It is determined by comparing the reflected power (power that is not absorbed by the antenna and is instead reflected back) to the TX power (power transmitted by the transmitter). A higher VSWR indicates a greater amount of power being reflected back, which can lead to inefficiencies and potential damage to the transmitter. Therefore, the correct answer is to compare the reflected power to the TX power.

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  • 9. 

    The frequencies created by the heterodyning process in an amplitude-modulated transmitter modulator are the

    • Two original frequencies

    • Sum of and difference between the tow original frequencies

    • Sum of the two original frequencies and two original frequencies

    Correct Answer
    A. Sum of and difference between the tow original frequencies
    Explanation
    The heterodyning process in an amplitude-modulated transmitter modulator involves mixing two original frequencies. This process results in the creation of two new frequencies - the sum of the two original frequencies and the difference between them. Therefore, the correct answer is that the frequencies created by the heterodyning process are the sum of and difference between the two original frequencies.

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  • 10. 

    The ability of the radio receiver to reproduce weak signals is called

    • Reproduction

    • Sensitivity

    • Reception

    Correct Answer
    A. Sensitivity
    Explanation
    Sensitivity refers to the ability of a radio receiver to reproduce weak signals. It determines how well the receiver can detect and amplify low-intensity signals, allowing for better reception and clarity of the transmitted information. A receiver with high sensitivity is able to capture and process weak signals more effectively, resulting in improved performance in areas with low signal strength or interference.

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  • 11. 

    In a frequency-shift radar system, what is the relationship between a transmitter/receiver and an aircraft when no frequency shift between them can be measured?

    • They are a constant distance away form each other

    • The aircraft is not reflection any of the radar pulses

    • The aircraft is flying away from the transmitter/receiver

    Correct Answer
    A. They are a constant distance away form each other
    Explanation
    When no frequency shift between the transmitter/receiver and the aircraft can be measured in a frequency-shift radar system, it indicates that they are a constant distance away from each other. This means that there is no change in the frequency of the radar signal as it is reflected back from the aircraft. This could occur when the aircraft is stationary or moving directly towards or away from the transmitter/receiver, resulting in a constant distance between them. It suggests that there is no relative motion between the two entities.

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  • 12. 

    In a frequecny-shift radar system, what is the relationship between a transmitter/receiver and an aircraft when the received frequency is higher than the transmitted frequency?

    • The aircraft is not reflecting any of the radar-pulses

    • The aircraft is flying towards the transmitter receiver

    • The aircraft is flying away from the transmitter receiver

    Correct Answer
    A. The aircraft is flying towards the transmitter receiver
    Explanation
    When the received frequency is higher than the transmitted frequency in a frequency-shift radar system, it indicates that the aircraft is flying towards the transmitter/receiver. This is because when an object is moving towards the radar system, the frequency of the reflected radar pulses increases due to the Doppler effect. Therefore, the higher received frequency suggests that the aircraft is approaching the transmitter/receiver.

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  • 13. 

    When two signals are received simultaneously on the same operating net, the HAVE QUICK II radio automatically goes into conferencing by

    • Resetting the net number for communication

    • Setting the receiver to narrowband reception

    • Offsetting the second transmitter frequency by 25Khz

    Correct Answer
    A. Offsetting the second transmitter frequency by 25Khz
    Explanation
    When two signals are received simultaneously on the same operating net, the HAVE QUICK II radio automatically goes into conferencing by offsetting the second transmitter frequency by 25Khz. This means that the second transmitter's frequency is adjusted by 25Khz to avoid interference and allow for clear communication. This offsetting helps to separate the two signals and ensure that they can be received and understood without interference or overlap.

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  • 14. 

    What is produced in the pulse-modulation radar system by heterodyning?

    • Very-low frequency

    • Very-hight frequency

    • Intermediate-frequency

    Correct Answer
    A. Intermediate-frequency
    Explanation
    In a pulse-modulation radar system, heterodyning refers to the process of combining two frequencies to produce a third frequency. In this case, the pulse-modulation radar system produces an intermediate-frequency signal through heterodyning. This intermediate-frequency signal is then used for further processing and analysis in the radar system.

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  • 15. 

    In the arc-190 high-frequency (hf) radio system, the HF coupler matches the impedance of the antenna to the receiver-transmitter in order to

    • Increase the voltage standing wave ratio

    • Give maximum power transfer

    • Increase transmitter selectivity

    Correct Answer
    A. Give maximum power transfer
    Explanation
    The HF coupler in the arc-190 high-frequency radio system matches the impedance of the antenna to the receiver-transmitter in order to give maximum power transfer. This means that it optimizes the transfer of power from the transmitter to the antenna, ensuring that the maximum amount of power is efficiently transmitted. By matching the impedance, the coupler minimizes signal loss and maximizes the power delivered to the antenna, resulting in effective communication.

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  • 16. 

    A very-high frequency frequency-modulated radio is mainly used on aircraft that

    • Contact army ground troops

    • Use airforce-controlled airfields

    • Contact airborne tankers for refueling

    Correct Answer
    A. Contact army ground troops
    Explanation
    A very-high frequency frequency-modulated radio is mainly used on aircraft to contact army ground troops. This type of radio allows for clear and reliable communication between the aircraft and the troops on the ground. It is essential for coordinating operations, relaying important information, and ensuring effective collaboration between the aircraft and the army ground troops.

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  • 17. 

    Which component in a pulse-modulation radar system shapes the radio-frequency energy into a narrow beam?

    • Antenna

    • Indicator

    • Transmitter

    Correct Answer
    A. Antenna
    Explanation
    The antenna in a pulse-modulation radar system shapes the radio-frequency energy into a narrow beam. Antennas are designed to focus and direct the electromagnetic waves in a specific direction, allowing the radar system to accurately detect and track targets. By shaping the radio-frequency energy into a narrow beam, the antenna helps to improve the radar system's range, accuracy, and resolution.

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  • 18. 

    When is the radar altimeter height indicator OFF flag not displayed?

    • The height indicator is turned off

    • Power to the radar altimeter is lost

    • The radar altimeter is tracking the terrain

    Correct Answer
    A. The radar altimeter is tracking the terrain
    Explanation
    The radar altimeter measures the height above the ground or terrain. When it is tracking the terrain, it means that it is actively sensing and displaying the height information. Therefore, in this situation, the OFF flag will not be displayed because the radar altimeter is functioning properly and providing accurate height readings.

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  • 19. 

    Which radar set line replaceable unit performs highly accurate electronic beam steering?

    • Radar transmitter

    • Radar data terminal

    • Low observable antenna

    Correct Answer
    A. Low observable antenna
    Explanation
    The low observable antenna is the correct answer because it is designed to perform highly accurate electronic beam steering in a radar set. This type of antenna is specifically engineered to minimize its detectability by reducing its radar cross-section, making it difficult for enemy radar systems to detect. It utilizes advanced technology to steer the radar beam precisely and accurately, allowing for effective surveillance and tracking capabilities while maintaining a low profile.

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  • 20. 

    Which radar altimeter mode is initiated when on insufficient amount of return video is present during the keyed gain control gate?

    • Standby

    • Ground map

    • Search/loss of track

    Correct Answer
    A. Search/loss of track
    Explanation
    When there is an insufficient amount of return video present during the keyed gain control gate, it indicates that the radar is unable to track or locate a target. In this situation, the radar altimeter mode that is initiated is the "search/loss of track" mode. This mode is used to search for a target or to indicate that the radar has lost track of a target.

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  • 21. 

    Which radar application is used primarily as an aid to navigation?

    • Search

    • Ground mapping

    • Terrain-following

    Correct Answer
    A. Search
    Explanation
    The radar application primarily used as an aid to navigation is the "search" radar. This type of radar is specifically designed to detect and locate objects or targets in a wide area, such as ships, aircraft, or other navigational aids. It provides a broad coverage and helps in identifying potential obstacles or hazards, ensuring safe navigation and preventing collisions.

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  • 22. 

    Two fundamental sections of the frequency-modulated receiver that are electrically different from those in the amplitude-modulated receiver are the

    • Discriminator and limiter

    • Limiter and audio amplifier

    • Local oscillator and detctor

    Correct Answer
    A. Discriminator and limiter
    Explanation
    In a frequency-modulated receiver, the discriminator and limiter are two fundamental sections that are electrically different from those in an amplitude-modulated receiver. The discriminator is responsible for converting the frequency variations in the received signal into corresponding voltage variations, allowing the demodulation of the FM signal. On the other hand, the limiter limits the amplitude of the received signal to a constant level, allowing for better noise rejection and signal quality. Therefore, the correct answer is discriminator and limiter.

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  • 23. 

    A receiving radio antenna receives radio-frequency signals by

    • Removing the radio-frequency carrier wave

    • Converting energy to magnetic and electrical fields of force

    • Electromagnetic fields impressing a voltage across the antenna, thus causing current to flow

    Correct Answer
    A. Electromagnetic fields impressing a voltage across the antenna, thus causing current to flow
    Explanation
    When a receiving radio antenna receives radio-frequency signals, it does so by electromagnetic fields impressing a voltage across the antenna. This means that the radio-frequency signals create electromagnetic fields that induce a voltage across the antenna, causing a current to flow. This current carries the information embedded in the radio-frequency signals, allowing the antenna to receive and interpret the signals.

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  • 24. 

    In a frequency-shift radar system, the doppler principle makes it possible to instantaneously sense and measure

    • Altitude and ground track

    • Target elevation and speed

    • Ground speed and drift angle

    Correct Answer
    A. Ground speed and drift angle
    Explanation
    The doppler principle in a frequency-shift radar system allows for the measurement of ground speed and drift angle. The doppler principle states that the frequency of a wave will change if the source of the wave is moving relative to the observer. In a radar system, this principle is used to measure the change in frequency of the reflected wave from a moving target. By analyzing this change in frequency, the radar system can determine the ground speed (speed of the target relative to the ground) and the drift angle (angle between the target's direction of motion and the ground track).

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  • 25. 

    What radar set component provides stabilized pitch and roll reference data for control of antenna orientation, despite changes in aircraft attitude?

    • Am-853b

    • C-1242a

    • Cn-221a

    Correct Answer
    A. Cn-221a
    Explanation
    The CN-221A radar set component provides stabilized pitch and roll reference data for control of antenna orientation, despite changes in aircraft attitude.

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  • 26. 

    A transmitting radio antenna is considered to be a transducer because it 

    • Transmits radio-frequency energy to distant locations

    • Converts energy to magnetic and electrical fields of forces

    • Creates current oscillations to induce radio-frequency energy

    Correct Answer
    A. Converts energy to magnetic and electrical fields of forces
    Explanation
    A transmitting radio antenna is considered to be a transducer because it converts energy to magnetic and electrical fields of forces. This means that it takes electrical energy and converts it into a combination of magnetic and electrical fields, which are then transmitted as radio-frequency energy to distant locations.

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  • 27. 

    If the external blower for an arc-190 high frequency radio system is overheating, it causes a receiver-transmitter fault and

    • Keeps the coupler from tuning

    • Reduces the external blower speed

    • Keeps the transmitter from functioning

    Correct Answer
    A. Keeps the transmitter from functioning
    Explanation
    If the external blower for an arc-190 high frequency radio system is overheating, it will cause a fault in the receiver-transmitter. This fault will then keep the transmitter from functioning properly.

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  • 28. 

    To which item does the radar sets dual-channel beam steering controller selectively send digital phasing and polarization commands?

    • Phase control module

    • Roll electronics assembly

    • Roll resolver power supply

    Correct Answer
    A. Phase control module
    Explanation
    The radar sets dual-channel beam steering controller selectively sends digital phasing and polarization commands to the phase control module.

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  • 29. 

    To achieve amplitude modulation, what device is used to ensure the output signal contains frequencies not present in the input signal?

    • Power amp

    • Balanced amp

    • Non-linear amplifier

    Correct Answer
    A. Non-linear amplifier
    Explanation
    A non-linear amplifier is used to achieve amplitude modulation by introducing frequencies that are not present in the input signal. Unlike linear amplifiers, which only amplify the input signal without introducing any additional frequencies, non-linear amplifiers modify the input signal by distorting its waveform. This distortion creates new frequencies in the output signal, allowing for the desired amplitude modulation effect.

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  • 30. 

    In a typical amplitude-modulated superheterodyne receiver, the process used to tune two or more circuits with a single control is called

    • Slug tuning

    • Ganged tuning

    • Parallel tuning

    Correct Answer
    A. Ganged tuning
    Explanation
    Ganged tuning is the process used in a typical amplitude-modulated superheterodyne receiver to tune two or more circuits with a single control. This means that when the control is adjusted, it simultaneously adjusts the tuning of multiple circuits in the receiver. This allows for easier and more efficient tuning of the receiver, as multiple circuits can be tuned at once, ensuring proper alignment and synchronization.

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  • 31. 

    The screen display on newer types of pulse modulation radar indicator is called

    • A map

    • A pulse

    • A sweep

    Correct Answer
    A. A map
    Explanation
    The screen display on newer types of pulse modulation radar indicators is referred to as a map. This suggests that the display provides a visual representation of the radar data in a map-like format. This could include information such as geographical features, targets, and other relevant data points. The term "a map" accurately describes the purpose and functionality of the screen display in these radar indicators.

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  • 32. 

    In a frequency-modulated signal, the amount of frequency modulation is controlled by the modulating signals

    • Frequency

    • Amplitude

    • Phase

    Correct Answer
    A. Amplitude
    Explanation
    In a frequency-modulated signal, the amount of frequency modulation is controlled by the modulating signals. This means that the modulating signals determine how much the frequency of the carrier signal varies. The amplitude of the carrier signal remains constant, while the frequency changes according to the modulating signals. Therefore, the correct answer is amplitude.

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  • 33. 

    The dimensions of a wave guide determine the wave guide's

    • Frequency and phase shift and powerloss

    • Frequency and power-handling capabilities

    • Voltage standing wave ration and power-handling ability

    Correct Answer
    A. Frequency and power-handling capabilities
    Explanation
    The dimensions of a waveguide determine its frequency and power-handling capabilities. The frequency of a waveguide is determined by its dimensions because different dimensions allow for the propagation of different frequencies. The power-handling capabilities of a waveguide are also influenced by its dimensions as they determine the maximum power that can be transmitted through the waveguide without causing damage or significant power loss. Therefore, the dimensions of a waveguide play a crucial role in determining its frequency range and power-handling capabilities.

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  • 34. 

    What is the transmitted frequency when a HF radio control is set to 27.5 Mhz, the signal is modulated by a 1000-hz tone, and lower sideband is selected?

    • 26.500Mhz

    • 27.499Mhz

    • 27.501Mhz

    Correct Answer
    A. 27.499Mhz
    Explanation
    When a HF radio control is set to 27.5 Mhz and modulated by a 1000-hz tone, the lower sideband is selected. Lower sideband modulation involves suppressing the carrier frequency and the upper sideband, leaving only the lower sideband. The transmitted frequency is then calculated by subtracting the modulating frequency (1000 Hz) from the carrier frequency (27.5 Mhz). Therefore, the transmitted frequency would be 27.5 Mhz - 1 kHz = 27.499 Mhz.

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  • 35. 

    The frequency range of the arc-186 vhf radio receiver in the FM mode is from

    • 30 to 87.975 Mhz

    • 38 to 87.975 Mhz

    • 108 to 151.975 Mhz

    Correct Answer
    A. 30 to 87.975 Mhz
    Explanation
    The correct answer is 30 to 87.975 Mhz. This frequency range is within the VHF (Very High Frequency) band, which typically spans from 30 to 300 Mhz. The FM (Frequency Modulation) mode is commonly used for VHF radio communication. Therefore, a VHF radio receiver operating in FM mode would have a frequency range within the VHF band, such as 30 to 87.975 Mhz.

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  • 36. 

    And advantage of the remote HAVE QUICK II configuration over the panel-mount configuration in an aircraft is it

    • Is more convenient for maintenance

    • Can be used with a remote channel indicator

    • Reduces cost by using existing aircraft wiring

    Correct Answer
    A. Reduces cost by using existing aircraft wiring
    Explanation
    The advantage of the remote HAVE QUICK II configuration over the panel-mount configuration in an aircraft is that it reduces cost by using existing aircraft wiring. This means that there is no need for additional wiring installation, saving both time and money. The remote configuration utilizes the existing wiring infrastructure of the aircraft, making it a more cost-effective option compared to the panel-mount configuration.

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  • 37. 

    A major draw back in using a single-sideband (ssb) receiver over and amplitude-modulated (am) receiver is the

    • Need for critical frequency stability

    • Ssb receiver has a narrower bandpass

    • Am receiver requires only one oscillator circuit

    Correct Answer
    A. Need for critical frequency stability
    Explanation
    The major drawback in using a single-sideband (SSB) receiver over an amplitude-modulated (AM) receiver is the need for critical frequency stability. This means that the SSB receiver requires a more precise and stable frequency in order to properly demodulate the signal. In contrast, an AM receiver only requires one oscillator circuit, which makes it less demanding in terms of frequency stability. Additionally, the SSB receiver has a narrower bandpass, which can limit its ability to receive a wide range of frequencies.

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  • 38. 

    The radar altimeter test button provides the capability for testing the low-altitude fly-up circuits in the

    • Radar data terminals and terrain following acu's

    • Rdr data terminals and ground following acu's

    • Tf acu's and delivery acu's

    Correct Answer
    A. Radar data terminals and terrain following acu's
    Explanation
    The radar altimeter test button is used to test the low-altitude fly-up circuits in the radar data terminals and terrain following ACUs. This means that when the test button is pressed, it allows for the evaluation of the functionality and performance of these specific components. The radar data terminals are responsible for processing and displaying radar information, while the terrain following ACUs are in charge of controlling the aircraft's altitude based on the radar data. Therefore, testing these circuits is crucial to ensure the proper functioning of the radar altimeter system.

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  • 39. 

    In an amplitude-modulated receiver, the detector circuit responds only to the 

    • Rate of frequency deviation of the intermediate frequency signal

    • Amplitude variations of the intermediate frequency signal

    • Frequency variations of the intermediate-frequency

    Correct Answer
    A. Amplitude variations of the intermediate frequency signal
    Explanation
    The correct answer is "amplitude variations of the intermediate frequency signal." In an amplitude-modulated receiver, the detector circuit is designed to detect and extract the audio signal from the carrier wave by responding to the variations in the amplitude of the intermediate frequency signal. The amplitude variations represent the information being carried in the modulated signal, such as sound or data, and the detector circuit is responsible for demodulating and extracting this information for further processing.

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  • 40. 

    The frequency range of the arc-186 very-high frequency radio receiver in the amplitude modulation mode is from

    • 30 to 87.975 Mhz

    • 38 to 87.975 Mhz

    • 108 to 151.975 Mhz

    Correct Answer
    A. 108 to 151.975 Mhz
    Explanation
    The correct answer is 108 to 151.975 Mhz. This frequency range is specified for the arc-186 very-high frequency radio receiver in the amplitude modulation mode. It means that this radio receiver is capable of receiving signals within this frequency range when operating in the amplitude modulation mode.

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  • 41. 

    In a signal-sideband system, which mode of operation transmits both sidebands and deletes the carrier?

    • Independent sideband

    • Singe-sideband transmission

    • Amplitude-modulated equivalent

    Correct Answer
    A. Independent sideband
    Explanation
    In a signal-sideband system, the independent sideband mode of operation transmits both sidebands and deletes the carrier. This means that the carrier signal, which is the unmodulated signal in an amplitude modulation system, is removed from the transmitted signal. The independent sideband mode allows for efficient use of bandwidth by transmitting only the necessary information contained in the sidebands, without the need for the carrier signal.

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  • 42. 

    In a single-sideband transmitter, the balance modulator's output consists of the 

    • Carrier and upper and lower sidebands

    • Upper and lower sidebands

    • Lower sideband only

    Correct Answer
    A. Upper and lower sidebands
    Explanation
    In a single-sideband transmitter, the balance modulator's output consists of the carrier and upper and lower sidebands. This means that the modulator generates two additional signals, one above the carrier frequency (upper sideband) and one below the carrier frequency (lower sideband). These sidebands contain the information that needs to be transmitted, while the carrier frequency helps in the demodulation process at the receiver end. By transmitting only the sidebands and not the carrier, single-sideband modulation allows for more efficient use of bandwidth and power.

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  • 43. 

    The radio-frequency line that has uniform capacitance between the conductors throughout the length of the line is the 

    • Shielded pair

    • Air coaxial line

    • Parallel two-wire

    Correct Answer
    A. Shielded pair
    Explanation
    A shielded pair is the radio-frequency line that has uniform capacitance between the conductors throughout the length of the line. This means that the capacitance remains constant along the entire length of the line, providing consistent performance and signal transmission. The shielded pair design helps to minimize interference and noise, making it suitable for applications where signal integrity is crucial.

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  • 44. 

    The an/arc-210 receiver/transmitter does not provide

    • Half-duplex, two way communications of normal and secure voice amplitude-modulated signals

    • Receiver-only mode of operation of normal and secure voice from 108.000 to 117.975 Mhz amplitude modulated

    • Transmit-only mode of operation of normal and secure voice from 108.000 to 117.9975 Mhz amplitude modulated

    Correct Answer
    A. Transmit-only mode of operation of normal and secure voice from 108.000 to 117.9975 Mhz amplitude modulated
    Explanation
    The correct answer is "transmit-only mode of operation of normal and secure voice from 108.000 to 117.9975 Mhz amplitude modulated." This means that the an/arc-210 receiver/transmitter is capable of transmitting normal and secure voice signals in the specified frequency range using amplitude modulation. However, it does not provide the capability for half-duplex, two-way communications or receiver-only mode of operation.

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  • 45. 

    In a frequency-modulated signal, the amount of separation between the sideband frequencies is equal to the

    • Carrier frequency

    • Rate of carrier swing

    • Modulating frequency

    Correct Answer
    A. Carrier frequency
    Explanation
    In a frequency-modulated signal, the amount of separation between the sideband frequencies is equal to the carrier frequency. This means that the sideband frequencies, which are produced as a result of modulation, are located symmetrically around the carrier frequency. The carrier frequency remains unchanged, while the sidebands are shifted in frequency according to the modulation. Therefore, the separation between the sideband frequencies is directly proportional to the carrier frequency.

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  • 46. 

    The purpose of the keyed automatic gain control gate while the radar altimeter is in track mode is to

    • Encompass and lock-on to the return video pulses

    • Be timed to overlap return pulse leading edge

    • Control the processing of the ground returns

    Correct Answer
    A. Control the processing of the ground returns
    Explanation
    The purpose of the keyed automatic gain control gate while the radar altimeter is in track mode is to control the processing of the ground returns. This means that the gate helps to regulate the amplification of the radar signals that are received from the ground. By controlling the gain, the gate ensures that the radar altimeter accurately detects and measures the distance between the aircraft and the ground. This helps in providing reliable altitude information to the pilot.

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  • 47. 

    On which frequencies can the arc-186 very-high frequency radio not transmit in the amplitude modulation mode?

    • 30 to 87.975 Mhz

    • 38 to 87.975 Mhz

    • 108 to 151.975 Mhz

    Correct Answer
    A. 108 to 151.975 Mhz
    Explanation
    The arc-186 very-high frequency radio cannot transmit in the amplitude modulation mode on frequencies ranging from 108 to 151.975 MHz.

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  • 48. 

    The low-pass filet in the automatic frequency control circuitry of a frequency-modulated transmitter is designed to prevent

    • The lower sideband from being transmitted

    • Correction volt changes caused by the modulating signals

    • Carrier frequency feedback from tuning the reactance modulator

    Correct Answer
    A. Correction volt changes caused by the modulating signals
    Explanation
    The low-pass filter in the automatic frequency control circuitry of a frequency-modulated transmitter is designed to prevent correction voltage changes caused by the modulating signals. This is because the modulating signals can introduce unwanted variations in the frequency of the transmitter's carrier signal. The low-pass filter helps to smooth out these variations and stabilize the carrier frequency, ensuring that the transmitted signal remains within the desired frequency range.

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  • 49. 

    Which very-high frequency radio system has the best chance of receiving a signal from a station located beyond the horizon?

    • Super-high frequency

    • Very-high frequency amplitude modulation

    • Very-high frequency frequency modulation

    Correct Answer
    A. Very-high frequency frequency modulation
    Explanation
    Very-high frequency frequency modulation has the best chance of receiving a signal from a station located beyond the horizon. This is because frequency modulation allows for better signal quality and less interference compared to amplitude modulation. Very-high frequency also has a shorter wavelength which allows it to diffract and bend around obstacles, enabling it to reach beyond the horizon.

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  • Mar 14, 2023
    Quiz Edited by
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  • Feb 17, 2011
    Quiz Created by
    Init2win
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