Langley CST - 3D151 Vol 2

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  • 1/100 Questions

    The process of condensation occurs when air particles are:

    • Pressurized, causing them to move closer together
    • Heated rapidly causing them to spread farther apart
    • Heated rapidly causing them to move closer together
    • Pressurized, causing them to be released to the atmosphere
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About This Quiz

The Langley CST - 3D151 VOL 2 quiz assesses knowledge in telecommunications and acoustics within a military context, focusing on sound frequencies, signal processing, and communication systems like DMS-100 used at Air Force bases.

3D151 Quizzes & Trivia

Quiz Preview

  • 2. 

    In hertz (Hz), what range of sound can the human ear detect?

    • 200 to 3,000

    • 20 to 20,000

    • 20 to 200,000

    • Up to 2,600

    Correct Answer
    A. 20 to 20,000
    Explanation
    The human ear can detect sound within the frequency range of 20 to 20,000 Hz. This range is commonly referred to as the audible range for humans. Frequencies below 20 Hz are known as infrasound and frequencies above 20,000 Hz are known as ultrasound, which are typically not audible to the human ear. Therefore, the correct answer is 20 to 20,000 Hz.

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  • 3. 

    The loudness of a sound is closely related to what part of the sine wave?

    • Amplitude

    • Frequency

    • Tone

    • Pitch

    Correct Answer
    A. Amplitude
    Explanation
    The loudness of a sound is closely related to the amplitude of the sine wave. Amplitude refers to the maximum displacement of the particles in a medium as a sound wave passes through it. A higher amplitude corresponds to a louder sound, as it represents a greater amount of energy being transferred by the wave. Therefore, the correct answer is amplitude.

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  • 4. 

    Noise may be introduced into speech signals by thermal agitation and:

    • Power variations

    • Amplitude variations

    • Black body raditation

    • Molecular breakdown

    Correct Answer
    A. Black body raditation
    Explanation
    Noise can be introduced into speech signals by various factors, including thermal agitation and black body radiation. Thermal agitation refers to the random movement of particles due to their thermal energy, which can cause fluctuations in the signal. Black body radiation refers to the emission of electromagnetic radiation by a perfect black body, which can also contribute to the introduction of noise in speech signals. Therefore, black body radiation is a valid explanation for the introduction of noise in speech signals.

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  • 5. 

    What is the maximum number of ports that a Meridian System Logic (MSL)-100 will support?

    • 10,000

    • 30,000

    • 100,000

    • 300,000

    Correct Answer
    A. 30,000
    Explanation
    The maximum number of ports that a Meridian System Logic (MSL)-100 will support is 30,000. This means that the MSL-100 can handle a large number of connections or devices simultaneously. It is important for the system to support a high number of ports in order to accommodate a large volume of incoming and outgoing data traffic. This capability is crucial for organizations or businesses that require a robust and scalable communication system.

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  • 6. 

    What type of digital signal (DS) protocol is used as a message carrier between the Digital Multiplex System (DMS)-Bus and the network modules (NM) and input/output controller (IOC)?

    • 1

    • 3

    • 30

    • 512

    Correct Answer
    A. 30
    Explanation
    The correct answer is 30. The question is asking about the type of digital signal protocol used as a message carrier between the Digital Multiplex System (DMS)-Bus and the network modules (NM) and input/output controller (IOC). The answer 30 suggests that the protocol used is likely DS-30, which is a digital signal protocol commonly used in telecommunications for transmitting voice and data signals.

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  • 7. 

    What type of information is transmitted on an Integrated Services Digital Network (ISDN) B-channel?

    • Call control

    • Supervisory

    • Signaling

    • User (voice or data)

    Correct Answer
    A. User (voice or data)
    Explanation
    On an Integrated Services Digital Network (ISDN) B-channel, user information is transmitted. This includes both voice and data from the user. The B-channel is responsible for carrying the actual content of the communication, whether it is a phone conversation or data transfer. This is in contrast to other types of information that may be transmitted on ISDN, such as call control, supervisory, or signaling information, which are not directly related to the user's content.

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  • 8. 

    What component in the video teleconferencing (VTC) system converts analog signals to digital signals?

    • Camera

    • Coder/decoder (CODEC)

    • Network termination 1

    • Central processing unit (CPU)

    Correct Answer
    A. Coder/decoder (CODEC)
    Explanation
    The correct answer is the coder/decoder (CODEC). In a video teleconferencing (VTC) system, the CODEC is responsible for converting analog signals, such as those from a camera, into digital signals that can be transmitted over a network. The CODEC also decodes digital signals received from the network back into analog signals for display on a screen or monitor. It plays a crucial role in ensuring the compatibility and quality of audio and video signals in a VTC system.

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  • 9. 

    How many channels are used when a voice over Internet Protocol (VoIP) session is established between a private branch exhange (PBX) and another IP host?

    • One, they share the same channel

    • Two, one for each direction

    • Three, two to transmit/receive and one to signal

    • Four, two to transmit and two to receive

    Correct Answer
    A. Two, one for each direction
    Explanation
    When a voice over Internet Protocol (VoIP) session is established between a private branch exchange (PBX) and another IP host, two channels are used, one for each direction. This means that there is a separate channel for transmitting audio from the PBX to the IP host, and another channel for transmitting audio from the IP host to the PBX. This allows for bidirectional communication between the two devices during the VoIP session.

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  • 10. 

    What component of voice over Internet Protocol (VoIP) provides call management functions in a defined local area called a zone?

    • Gateway

    • Gatekeeper

    • Terminal adapter

    • Multipoint control unit (MCU)

    Correct Answer
    A. Gatekeeper
    Explanation
    A gatekeeper is a component of Voice over Internet Protocol (VoIP) that provides call management functions in a defined local area called a zone. It acts as a central control point for managing and directing calls within the network. It authenticates and authorizes users, controls bandwidth allocation, manages call routing, and provides other administrative functions. A gatekeeper ensures efficient and secure communication by regulating access and managing resources in the VoIP network.

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  • 11. 

    What are frequencies from 30 to 300 megahertz (MHz) internationally designated as?

    • High

    • Medium

    • Very high

    • Ultra high

    Correct Answer
    A. Very high
    Explanation
    Frequencies from 30 to 300 megahertz (MHz) are internationally designated as "Very high." This range of frequencies falls within the VHF (Very High Frequency) band, which is commonly used for various purposes such as FM radio broadcasting, television broadcasting, and aviation communication.

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  • 12. 

    The total resistive properties of a circuit when resistance, capacitive reactance, and inductive reactance are formulated together is called:

    • Attenuation

    • Impedance

    • Resistance

    • Distortion

    Correct Answer
    A. Impedance
    Explanation
    Impedance refers to the total resistive properties of a circuit when resistance, capacitive reactance, and inductive reactance are combined. It is a measure of how much a circuit resists the flow of alternating current. Impedance takes into account both the resistance and reactance components of a circuit, and it is represented by a complex number that includes both magnitude and phase. Impedance is important in analyzing and designing electrical circuits, as it determines how the circuit will respond to AC signals and affects the overall performance of the circuit.

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  • 13. 

    For best communications, the transmitting antenna:

    • Should be circular and the receiving antenna horizontal

    • Should be vertical and receiving antenna horizontal

    • Should be horizontal and receiving antenna vertical

    • And receiving antenna should have the same polarization

    Correct Answer
    A. And receiving antenna should have the same polarization
    Explanation
    To ensure optimal communication, it is important for the transmitting and receiving antennas to have the same polarization. Polarization refers to the orientation of the electric field of the radio waves being transmitted. When the polarization of both antennas is aligned, it allows for better reception and transmission of the signals. If the antennas have different polarizations, there may be significant signal loss and reduced communication efficiency. Therefore, having the same polarization between the transmitting and receiving antennas is crucial for effective communication.

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  • 14. 

    What standard antenna is used for antenna gain comparison?

    • Whip

    • Dipole

    • Isotropic

    • Parabolic

    Correct Answer
    A. Isotropic
    Explanation
    The correct answer is Isotropic. An isotropic antenna is a theoretical concept used as a reference for antenna gain comparison. It radiates equally in all directions and has a gain of 0 dBi. It is used as a standard for measuring the performance of other antennas, which are compared to the isotropic antenna to determine their gain.

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  • 15. 

    When the gain of an anisotropic radiator is compared to the isotropic radiator, the stronger signal of the directional antenna is expressed as:

    • Decibels (dB) gain

    • DB plus

    • Over voltage

    • Over watts

    Correct Answer
    A. Decibels (dB) gain
    Explanation
    The gain of an antenna refers to its ability to focus and amplify signals in a specific direction. When comparing the gain of an anisotropic radiator (directional antenna) to an isotropic radiator (omnidirectional antenna), the stronger signal of the directional antenna is expressed in decibels (dB) gain. Decibels is a logarithmic unit used to measure the ratio of power or intensity, and in this case, it quantifies the increase in signal strength provided by the directional antenna compared to the isotropic radiator.

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  • 16. 

    What limits a direct wave to normally less than 20 miles?

    • Curvature of the earth

    • Buildings in the area

    • Topographic features

    • Physical limitation of the frequency attenuation

    Correct Answer
    A. Curvature of the earth
    Explanation
    Direct waves, also known as line-of-sight waves, travel in a straight line from the transmitter to the receiver. However, the curvature of the earth limits the range of these waves. As the distance between the transmitter and receiver increases, the earth's curvature causes the direct wave to gradually bend away from the receiver, resulting in a loss of signal strength. This phenomenon is particularly noticeable at longer distances, and it is the reason why direct waves are typically limited to less than 20 miles.

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  • 17. 

    Which type of precipitation attenuates radio frequency (RF) energy just like rain?

    • Ice

    • Fog

    • Hail

    • Snow

    Correct Answer
    A. Fog
    Explanation
    Fog is the correct answer because it attenuates radio frequency (RF) energy just like rain. Fog consists of tiny water droplets suspended in the air, which can cause the RF energy to scatter and be absorbed, leading to a decrease in signal strength. This attenuation effect is similar to what happens with rain, where the water droplets in the atmosphere interfere with the transmission of RF signals. Therefore, fog can have a similar impact on RF communication as rain does.

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  • 18. 

    What ratio is used to measure the desired signal strength relative to the background noise?

    • Percentage of modulation

    • Signal-to-noise

    • Selectivity

    • Distortion

    Correct Answer
    A. Signal-to-noise
    Explanation
    The ratio used to measure the desired signal strength relative to the background noise is called signal-to-noise. This ratio indicates how much stronger the desired signal is compared to the unwanted noise present in the background. A higher signal-to-noise ratio indicates a stronger and clearer signal, while a lower ratio indicates a weaker and more distorted signal. It is an important measure in various fields, including telecommunications, audio processing, and data analysis.

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  • 19. 

    Which personal wireless communications system (PWCS) device's original intent was for use by family, friends, and associates to communicate among themselves within a small area?

    • Pager

    • Land mobile radio (LMR)

    • Family radio service (FRS)

    • Personal digital assistant (PDA)

    Correct Answer
    A. Family radio service (FRS)
    Explanation
    The Family Radio Service (FRS) device was originally intended for use by family, friends, and associates to communicate among themselves within a small area. FRS devices are commonly used for recreational activities, such as camping or hiking, where a group needs to stay in contact with each other. These devices operate on specific channels and have limited range, making them suitable for short-range communication within a small group.

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  • 20. 

    In hertz (Hz), what is the actual voice frequency band?

    • 300 to 1,600

    • 300 to 2,600

    • 300 to 3,400

    • 300 to 3,800

    Correct Answer
    A. 300 to 3,400
    Explanation
    The actual voice frequency band, measured in hertz (Hz), ranges from 300 to 3,400. This means that the human voice typically produces sound waves within this frequency range.

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  • 21. 

    Which models of end offices in the Digital Multiplex System (DMS) family are commonly used at Air Force bases to provide base telephone services?

    • DMS-100 and Meridian System Logic (MSL)-100

    • DMS-100/200 and MSL-100

    • DMS-100/200 and DMS-200

    • DMS-200 and MSL-100

    Correct Answer
    A. DMS-100 and Meridian System Logic (MSL)-100
    Explanation
    The correct answer is DMS-100 and Meridian System Logic (MSL)-100. These models of end offices in the Digital Multiplex System (DMS) family are commonly used at Air Force bases to provide base telephone services.

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  • 22. 

    Which type link is normally used to interconnect two peripheral modules (PM) in the Digital Multiplex System (DMS)?

    • Digital signal (DS)-1

    • DS-30A

    • DS-32

    • T1A

    Correct Answer
    A. DS-30A
    Explanation
    DS-30A is the correct answer because it is the type of link that is typically used to interconnect two peripheral modules (PM) in the Digital Multiplex System (DMS). The DS-30A link provides a transmission rate of 30 Mbps, which is suitable for connecting peripheral modules and transferring data between them efficiently.

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  • 23. 

    What is the mounting bracket called on which transmission or swtiching equipment is mounted in a Digital Multiplex System (DMS)?

    • Bay

    • Card

    • Shelf

    • Frame

    Correct Answer
    A. Bay
    Explanation
    In a Digital Multiplex System (DMS), the mounting bracket on which transmission or switching equipment is mounted is called a "Bay." This term is commonly used in telecommunications to refer to a specific area or enclosure where the equipment is housed. Bays are designed to provide a secure and organized space for the installation and maintenance of various components, such as cards, shelves, and frames.

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  • 24. 

    What contains bays of the same functional equipment?

    • Bay

    • Card

    • Shelf

    • Frame

    Correct Answer
    A. Frame
    Explanation
    A frame contains bays of the same functional equipment. Bays are compartments or sections within a frame that hold specific equipment. Frames are typically used in industries such as telecommunications or data centers to organize and house equipment efficiently. Each bay within a frame can hold similar equipment, making it easier to manage and access.

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  • 25. 

    Which Digital Multiplex System (DMS) component uses 16-bit Motorola 68000 or 8-bit Intel microprocessors?

    • A device controller

    • The network message controller

    • A peripheral module's (PM) peripheral processor (PP)

    • The computing module's (CM) central processing unit (CPU)

    Correct Answer
    A. A peripheral module's (PM) peripheral processor (PP)
    Explanation
    The peripheral module's (PM) peripheral processor (PP) uses either a 16-bit Motorola 68000 or an 8-bit Intel microprocessor in the Digital Multiplex System (DMS). This component is responsible for controlling and managing the peripheral devices connected to the DMS. It handles the communication between the peripheral devices and the computing module's central processing unit (CPU). The choice of microprocessor depends on the specific requirements and capabilities of the DMS.

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  • 26. 

    How many channels of data does each digital signal (DS) 30 speech link carry?

    • 30

    • 32

    • 34

    • 36

    Correct Answer
    A. 32
    Explanation
    Each digital signal (DS) 30 speech link carries 32 channels of data.

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  • 27. 

    Up to how many duplicated digital signals (DS)-30 links are used to connect a line group controller (LGC) to the network module (NM)?

    • 6

    • 8

    • 16

    • 24

    Correct Answer
    A. 16
    Explanation
    The line group controller (LGC) is connected to the network module (NM) using duplicated digital signals (DS)-30 links. The question is asking for the maximum number of DS-30 links that can be used for this connection. The correct answer is 16, which means that up to 16 DS-30 links can be used to connect the LGC to the NM.

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  • 28. 

    What is the first step in the pulse code modulation (PCM) process?

    • Discrete amplitudes are assigned to the sampling pulses

    • A binary code number is assigned to the sample

    • The quantizer limits the amplitude of the pulses

    • The analog signal is band-limited

    Correct Answer
    A. The analog signal is band-limited
    Explanation
    In pulse code modulation (PCM), the first step is to band-limit the analog signal. This means that the signal is filtered to remove any frequencies that are outside the desired range. Band-limiting is necessary to prevent aliasing, which can distort the signal during the sampling process. By limiting the bandwidth of the analog signal, it ensures that only the desired frequencies are captured accurately during the sampling process.

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  • 29. 

    In the pulse code modulation (PCM) process, changing the quantized samples into a binary word is called:

    • Encoding

    • Sampling

    • Quantization

    • Band limiting

    Correct Answer
    A. Encoding
    Explanation
    In the pulse code modulation (PCM) process, changing the quantized samples into a binary word is called encoding. This is because encoding involves converting the analog signal into a digital format by assigning specific binary codes to each quantized sample. The binary word represents the amplitude of the signal at a given point in time and is used for transmission or storage purposes. Sampling refers to the process of measuring the amplitude of the analog signal at regular intervals, quantization is the process of approximating the continuous analog signal into discrete levels, and band limiting refers to restricting the frequency range of the signal.

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  • 30. 

    What are the two major established Integrated Services Digital Network (ISDN) transmission rates?

    • Bearer rate interface and data rate interface

    • Basic rate interface and primary rate interface

    • Basic rate interface and secondary rate interface

    • Primary rate interface and secondary rate interface

    Correct Answer
    A. Basic rate interface and primary rate interface
    Explanation
    The correct answer is Basic rate interface and primary rate interface. ISDN is a telecommunications network that provides digital transmission of voice, video, and data over traditional telephone lines. The Basic rate interface (BRI) is designed for residential and small business use, offering two B channels for data and one D channel for signaling. The Primary rate interface (PRI) is intended for larger businesses, providing 23 B channels and one D channel in North America, and 30 B channels and one D channel in Europe. These two transmission rates are the major established options for ISDN connections.

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  • 31. 

    The Network Layer of the Open Systems Interconnection (OSI) model provides the:

    • Physical characteristics between the Integrated Services Digital Network (ISDN) interface and the network

    • Logical links between customer equipment and the circuit switch

    • Final preparation of the signal before it is routed

    • Actual routing of the signal

    Correct Answer
    A. Actual routing of the signal
    Explanation
    The Network Layer of the OSI model is responsible for the actual routing of the signal. This layer takes care of determining the best path for the data packets to travel from the source to the destination across different networks. It handles tasks such as addressing, packet forwarding, and routing protocols. By analyzing the network topology and making decisions based on routing tables, the Network Layer ensures that data packets are efficiently delivered to their intended destinations.

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  • 32. 

    One of the main purposes of the Integrated Services Digital Network (ISDN) handset telephone test set is to:

    • Detect noise

    • Insert tones

    • Verify a dial tone

    • Insert signal delay

    Correct Answer
    A. Verify a dial tone
    Explanation
    The main purpose of the Integrated Services Digital Network (ISDN) handset telephone test set is to verify a dial tone. This means that the test set is used to check if a dial tone is present and functioning properly on the telephone line. It ensures that the user can make outgoing calls successfully by confirming the availability of a dial tone.

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  • 33. 

    What is the frame rate in feet per second (FPS) for transmitting video teleconferencing data on the Integrated Services Digital Network (ISDN)?

    • 24

    • 30

    • 32

    • 64

    Correct Answer
    A. 30
    Explanation
    The frame rate in feet per second (FPS) for transmitting video teleconferencing data on the Integrated Services Digital Network (ISDN) is 30. This means that 30 frames of video are transmitted every second over the ISDN network.

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  • 34. 

    How many milliseconds should the one-way delay be from endpoint to endpoint in order to implement voice over Internet Protocol (VoIP)?

    • Less than 50

    • Less than 150

    • Greater than 50

    • Greater than 150

    Correct Answer
    A. Less than 150
    Explanation
    In order to implement voice over Internet Protocol (VoIP), the one-way delay from endpoint to endpoint should be less than 150 milliseconds. This is because any delay greater than this can result in noticeable voice quality degradation and communication issues. Therefore, to ensure smooth and real-time communication, it is important to keep the one-way delay below 150 milliseconds.

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  • 35. 

    What is the control system that generates a signal with a fixed relation to the phase of a reference signal and responds to both the frequency and the phase of the input signals?

    • Quality of service (QoS)

    • Remote control protocol (RCP)

    • Forward error correction (FEC)

    • Phase-locked loop (PLL)

    Correct Answer
    A. Phase-locked loop (PLL)
    Explanation
    A phase-locked loop (PLL) is a control system that generates a signal with a fixed relation to the phase of a reference signal. It not only responds to the frequency but also the phase of the input signals. In other words, a PLL locks onto the phase of a reference signal and adjusts the frequency and phase of its output signal accordingly. This makes it a suitable control system for applications that require precise synchronization and tracking of phase and frequency, such as in communication systems, audio/video equipment, and clock generation.

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  • 36. 

    The process of mixing or combining two frequencies in a nonlinear device in an amplitude modulated (AM) receiver is called:

    • Limiting

    • Amplifying

    • Heterodyning

    • Discriminating

    Correct Answer
    A. Heterodyning
    Explanation
    Heterodyning is the process of mixing or combining two frequencies in a nonlinear device in an amplitude modulated (AM) receiver. This technique is used to convert the received signal to a lower frequency, known as the intermediate frequency (IF), which is easier to process and amplify. By mixing the received signal with a local oscillator signal, a new frequency is generated in the IF range, allowing for easier filtering and amplification of the desired signal. Heterodyning is a crucial step in the demodulation process of an AM receiver.

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  • 37. 

    What component of a frequency modulated (FM) receiver removes the original signal from the sidebands and recreates the audio intelligence?

    • Limiter

    • Detector

    • Amplifier

    • Discriminator

    Correct Answer
    A. Discriminator
    Explanation
    The discriminator is the component of a frequency modulated (FM) receiver that removes the original signal from the sidebands and recreates the audio intelligence. It does this by demodulating the FM signal and converting it back into an audio signal. The discriminator is responsible for extracting the audio information from the FM carrier wave and restoring it to its original form.

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  • 38. 

    What characteristic enables a receiver to reproduce a desired signal from several closely spaced stations or from interfering frequencies?

    • Sensitivity

    • Selectivity

    • Fade margin

    • Thermal noise

    Correct Answer
    A. Selectivity
    Explanation
    Selectivity is the characteristic that enables a receiver to reproduce a desired signal from several closely spaced stations or from interfering frequencies. It refers to the ability of a receiver to separate and extract the desired signal while rejecting unwanted signals or interference. A selective receiver is able to filter out unwanted frequencies and only amplify and process the specific frequency or range of frequencies that it is tuned to receive. This allows for clear and accurate reproduction of the desired signal, even in the presence of nearby stations or interfering frequencies.

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  • 39. 

    What field provides the basis of radio frequency (RF) communications by detaching from the conductor and traveling through space?

    • Electric

    • Magnetic

    • Induction

    • Radiation

    Correct Answer
    A. Radiation
    Explanation
    Radiation is the correct answer because it refers to the process in which radio frequency (RF) signals detach from the conductor and travel through space. RF signals are electromagnetic waves that propagate through space without the need for a physical medium. This is the fundamental principle behind wireless communication systems such as radio, television, and cellular networks.

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  • 40. 

    What channel access method assigns each call a certain portion of time on a designated frequency?

    • Time division multiple access (TDMA)

    • Personal communications services (PCS)

    • Frequency division multiple access (FDMA)

    • Global system for mobile communications (GSM)

    Correct Answer
    A. Time division multiple access (TDMA)
    Explanation
    Time division multiple access (TDMA) is a channel access method that assigns each call a certain portion of time on a designated frequency. This means that multiple calls can be transmitted simultaneously by dividing the available time into smaller time slots. Each call is allocated a specific time slot, allowing multiple calls to share the same frequency without interfering with each other. TDMA is commonly used in cellular networks to maximize the efficiency of frequency spectrum utilization.

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  • 41. 

    Cell sites are generally thought of as being a:

    • Square

    • Octagon

    • Hexagon

    • Pentagon

    Correct Answer
    A. Hexagon
    Explanation
    Cell sites are generally thought of as being a hexagon because the coverage area of a cell site is typically divided into hexagonal shapes. This is because hexagons provide the most efficient and uniform coverage, allowing for the least amount of overlap and the best distribution of signal strength. The use of hexagons also helps to minimize interference between neighboring cell sites and maximize the overall capacity and performance of the cellular network.

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  • 42. 

    What conventional land mobile radio (LMR) device serves as the hub of a net?

    • Portable

    • Mobile

    • Repeater

    • Base station

    Correct Answer
    A. Base station
    Explanation
    A base station is the correct answer because it serves as the central hub of a network in conventional land mobile radio (LMR) systems. It is a fixed station that communicates with portable and mobile radios within its coverage area. The base station typically has a more powerful transmitter and receiver compared to portable and mobile devices, allowing it to provide wider coverage and better communication quality. It acts as a central control point for managing and coordinating communication activities within the network, making it an essential component for LMR systems.

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  • 43. 

    In trunked land mobile radio (LMR) systems, different user groups are known as:

    • Talkgroups

    • Channels

    • Packets

    • Nets

    Correct Answer
    A. Talkgroups
    Explanation
    In trunked land mobile radio (LMR) systems, different user groups are known as talkgroups. Talkgroups are a way to organize and categorize users within the system. Each talkgroup is assigned a unique identifier and users within the same talkgroup can communicate with each other. This allows for efficient and organized communication within the LMR system, as users can easily select and connect with the specific talkgroup they need to communicate with. Channels, packets, and nets are not the correct terms used to refer to user groups in trunked LMR systems.

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  • 44. 

    What type areas is International Mobile Satellite Organization (Inmarsat) coverage separated into?

    • Geographical

    • Continental

    • Regional

    • Ocean

    Correct Answer
    A. Ocean
    Explanation
    Inmarsat coverage is divided into ocean areas. This means that their satellite communication services are specifically designed to cover maritime regions and provide connectivity for ships and vessels at sea.

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  • 45. 

    The primary reason you measure the voltage across terminal or distribution frame protectors before removing and replacing them is to:

    • Make sure dangerous voltages are not present on the line

    • Prevent interruptions to critical circuits

    • Avoid activating alarm circuits

    • Verify the circuit is not in use

    Correct Answer
    A. Make sure dangerous voltages are not present on the line
    Explanation
    Before removing and replacing terminal or distribution frame protectors, it is important to measure the voltage across them to ensure that dangerous voltages are not present on the line. This is crucial for the safety of the person performing the task as well as to prevent any potential damage to the equipment or circuits. By measuring the voltage, one can determine if it is safe to proceed with the removal and replacement process without risking any harm or accidents.

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  • 46. 

    What's the difference between the basic access module (BAM) and the configurable access module (CAM)?

    • CAM provides a secure data network to local subscribers

    • BAM provides a secure data network to local subscribers

    • CAM has a fixed capability

    • BAM has a fixed capability

    Correct Answer
    A. BAM has a fixed capability
    Explanation
    BAM and CAM are both access modules that provide a secure data network to local subscribers. However, the difference lies in their capabilities. While CAM has a fixed capability, BAM also has a fixed capability. This suggests that both modules have a specific set of features or functions that cannot be modified or expanded upon.

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  • 47. 

    What is the shortest wavelength an antenna can be made resonant?

    • Quarter

    • Half

    • One

    • Two

    Correct Answer
    A. Half
    Explanation
    An antenna can be made resonant at the shortest wavelength by using a half-wavelength design. This means that the length of the antenna is half the wavelength of the signal it is designed to receive or transmit. This design allows for efficient transfer of energy between the antenna and the electromagnetic waves, maximizing the antenna's performance. Using a quarter-wavelength design would not be sufficient for resonant operation, as it would result in poor impedance matching and reduced efficiency.

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  • 48. 

    Which model of Digital Multiplex System (DMS)-100 family switches is installed in compact modular cabinets?

    • System load (SL)-1

    • DMS-100

    • DMS-200

    • Meridian System Logic (MSL)-100

    Correct Answer
    A. Meridian System Logic (MSL)-100
    Explanation
    The Meridian System Logic (MSL)-100 model of Digital Multiplex System (DMS)-100 family switches is installed in compact modular cabinets.

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  • 49. 

    What major area is connected to the central side (C-side) of a network module (NM) in the Digital Multiplex System (DMS)?

    • Control node (CN)

    • Peripheral module (PM)

    • Message controller (MC)

    • Central control

    Correct Answer
    A. Central control
    Explanation
    The central side (C-side) of a network module (NM) in the Digital Multiplex System (DMS) is connected to the central control. This means that the central control is the major area connected to the C-side of the NM. The central control is responsible for managing and controlling the overall operation of the DMS network. It coordinates the functions of various modules and ensures efficient communication within the system.

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Quiz Review Timeline (Updated): Mar 21, 2023 +

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  • Current Version
  • Mar 21, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Jun 02, 2017
    Quiz Created by
    Jordan
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