3d1x5 CDC Pool Of 100

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CDC Quizzes & Trivia

For use by 3D1X5 personnel for the purpose of CDC EOC testing.


Questions and Answers
  • 1. 

    What characteristic of frequency does a radar target moving towards the radar exhibit?

    • A.

      A lower frequency than the original broadcast

    • B.

      A higher frequency than the original broadcast

    • C.

      No apparent frequency change than the original broadcast

    • D.

      Oscillating lower and higher frequency changes in respect to the original broadcast

    Correct Answer
    B. A higher frequency than the original broadcast
    Explanation
    When a radar target is moving towards the radar, it exhibits a higher frequency than the original broadcast. This is known as the Doppler effect. As the target moves towards the radar, the waves are compressed, causing an increase in frequency. This increase in frequency can be detected by the radar system and used to determine the speed and direction of the target.

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  • 2. 

    What radar subassembly allows the radar system to transmit and receive from the same antenna?

    • A.

      Synchronizer

    • B.

      Transmitter

    • C.

      Modulator

    • D.

      Duplexer

    Correct Answer
    D. Duplexer
    Explanation
    A duplexer is a radar subassembly that allows the radar system to transmit and receive from the same antenna. It is responsible for separating the outgoing and incoming signals, allowing them to be transmitted and received without interference. This component is crucial in radar systems as it enables the system to alternate between transmitting and receiving signals using a single antenna, thereby optimizing the use of resources and ensuring efficient radar operation.

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  • 3. 

    An antenna is said to be reciprocal if

    • A.

      It is nonlinear

    • B.

      It transmits patterns

    • C.

      It contains ferrite devices

    • D.

      Its transmit and receive patterns are identical

    Correct Answer
    D. Its transmit and receive patterns are identical
    Explanation
    A reciprocal antenna is one that exhibits the same transmit and receive patterns. This means that the antenna will radiate electromagnetic waves in the same way when it is used for transmitting as it does when it is used for receiving signals. In other words, the antenna does not discriminate between transmitting and receiving signals and behaves in a symmetrical manner. This property is important in various applications, such as wireless communication systems, where the antenna's performance needs to be consistent for both transmitting and receiving signals.

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  • 4. 

    Which feedhorn is used only for receiving?

    • A.

      Active

    • B.

      Linear

    • C.

      Passive

    • D.

      Circular

    Correct Answer
    C. Passive
    Explanation
    Passive feedhorns are used only for receiving signals. Unlike active feedhorns, which can both receive and transmit signals, passive feedhorns are designed solely for the purpose of receiving signals. They do not have any active components or electronics that would allow for signal transmission. Therefore, passive feedhorns are the correct answer for this question.

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  • 5. 

    The shape of the beam of radar energy and its antenna pattern depend on the radar’s

    • A.

      Gain

    • B.

      Location

    • C.

      Purpose

    • D.

      Power

    Correct Answer
    C. Purpose
    Explanation
    The shape of the beam of radar energy and its antenna pattern depend on the radar's purpose. Different radar systems are designed for specific purposes, such as air traffic control, weather monitoring, or military surveillance. Each purpose requires a different beam shape and antenna pattern to effectively detect and track the desired targets. Therefore, the purpose of the radar system determines the specific characteristics of the beam and antenna pattern.

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  • 6. 

    The scanning method used by the radar system refers to the

    • A.

      Direction of energy into an appropriately shaped beam

    • B.

      Orientation of the electromagnetic wave as it travels through space

    • C.

      Motion of the antenna axis (of the beam) as the radar looks for an aircraft

    • D.

      Efficient launch and reception of electromagnetic energy in the atmosphere or space

    Correct Answer
    C. Motion of the antenna axis (of the beam) as the radar looks for an aircraft
    Explanation
    The scanning method used by the radar system refers to the motion of the antenna axis (of the beam) as the radar looks for an aircraft. This means that the radar system moves the antenna in a specific pattern or direction in order to scan the surrounding area for any aircraft. By moving the antenna, the radar system can cover a larger area and detect any objects within its range. This scanning method allows the radar system to effectively search for aircraft and track their movements.

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  • 7. 

    What scan is identified at the electronic countermeasure receiver by its regular intervals between illuminations?

    • A.

      Raster

    • B.

      Conical

    • C.

      Circular

    • D.

      Monopulse

    Correct Answer
    C. Circular
    Explanation
    Circular scan is identified at the electronic countermeasure receiver by its regular intervals between illuminations. This type of scan involves the antenna rotating in a circular pattern, covering a full 360 degrees. The regular intervals between illuminations refer to the consistent time intervals at which the antenna points in different directions during the scan. This scan pattern is commonly used in radar systems to provide full coverage of the surrounding area.

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  • 8. 

    Which scan radar is also used in the acquisition phase by some airborne intercept radars?

    • A.

      Raster

    • B.

      Conical

    • C.

      Circular

    • D.

      Monopulse

    Correct Answer
    A. Raster
    Explanation
    Some airborne intercept radars use the Raster scan radar in the acquisition phase. The Raster scan radar is a type of scanning technique that uses a series of parallel scan lines to cover a specific area. This scanning pattern allows the radar to quickly search and acquire targets within its field of view. By using the Raster scan radar in the acquisition phase, the airborne intercept radars can effectively detect and track potential targets in the surrounding airspace.

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  • 9. 

    What causes delayed, but separate, pulses?

    • A.

      Simultaneous reception of pulse-type information

    • B.

      Near-simultaneous reception of pulse-type information

    • C.

      Electromagnetic (EM) waves reach the receiving antenna by direct paths

    • D.

      EM waves reach the receiving antenna by indirect paths

    Correct Answer
    B. Near-simultaneous reception of pulse-type information
    Explanation
    Near-simultaneous reception of pulse-type information causes delayed, but separate, pulses. This means that the pulses are received in close succession, but with a slight delay between each pulse. This could be due to factors such as the distance between the transmitter and receiver, the speed of the electromagnetic waves, or any obstacles or interference that the waves encounter along their path. As a result, the pulses arrive at the receiving antenna at slightly different times, causing the delay in their reception.

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  • 10. 

    Attempts to reduce multipath effects on radar tracking accuracy include the use of

    • A.

      Off-axis tracking

    • B.

      Frequency agility

    • C.

      Monopulse radar

    • D.

      Off-boresight tracking

    Correct Answer
    B. Frequency agility
    Explanation
    Frequency agility refers to the ability of a radar system to rapidly change its operating frequency. This technique is used to mitigate the effects of multipath, which occurs when radar signals bounce off objects and arrive at the receiver through multiple paths. By changing the frequency, the radar can avoid or minimize the interference caused by these reflected signals, improving tracking accuracy. Therefore, frequency agility is an effective method to reduce multipath effects on radar tracking accuracy.

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  • 11. 

    What type of radar system uses a B-scan indicator?

    • A.

      Long-range surveillance

    • B.

      Airport surveillance

    • C.

      Precision approach

    • D.

      Weather

    Correct Answer
    C. Precision approach
    Explanation
    A radar system that uses a B-scan indicator is typically used for precision approach. Precision approach radar systems are designed to provide accurate and detailed information about the position and movement of aircraft during the final stages of landing. The B-scan indicator is a display feature that shows a cross-sectional view of the radar echoes, allowing for precise measurement of the aircraft's altitude and alignment with the runway. This type of radar system is crucial for ensuring safe and accurate landings, especially in low visibility conditions.

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  • 12. 

    What target information is provided by a plan-position indicator?

    • A.

      Azimuth only

    • B.

      Elevation only

    • C.

      Range and azimuth

    • D.

      Elevation and range

    Correct Answer
    C. Range and azimuth
    Explanation
    A plan-position indicator (PPI) provides information about the range and azimuth of a target. The range indicates the distance between the radar and the target, while the azimuth indicates the target's position in relation to the radar's reference point. By displaying both range and azimuth, the PPI can provide a comprehensive view of the target's location and movement in a two-dimensional plane.

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  • 13. 

    In a Raster scan indicator, how many vertical scan periods does it take to produce one complete picture?

    • A.

      1

    • B.

      2

    • C.

      3

    • D.

      4

    Correct Answer
    B. 2
    Explanation
    In a Raster scan indicator, it takes two vertical scan periods to produce one complete picture. This is because the raster scan process involves scanning the image from top to bottom, line by line. The first scan period covers the odd-numbered lines, while the second scan period covers the even-numbered lines. By combining the information from both scan periods, a complete picture is formed.

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  • 14. 

    The vacuum in a cathode-ray tube (CRT)

    • A.

      Prevents implosion if the CRT is broken

    • B.

      Keeps the phosphor coating from burning

    • C.

      Eliminates static charges on the deflection plates

    • D.

      Prevents collisions between electrons in the beam and air molecules

    Correct Answer
    D. Prevents collisions between electrons in the beam and air molecules
    Explanation
    The vacuum in a cathode-ray tube (CRT) prevents collisions between electrons in the beam and air molecules. When the CRT is in operation, an electron beam is produced and accelerated towards the screen. If there was air or any other gas present inside the tube, the electrons would collide with the gas molecules, causing scattering and loss of energy. This would result in a distorted image on the screen. By creating a vacuum inside the CRT, the path of the electrons remains unobstructed, allowing them to travel in a straight line and accurately hit the phosphor coating on the screen, producing a clear and focused image.

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  • 15. 

    An X pulse is present in a selective identification feature code train when

    • A.

      A Mode 4 reply is being received

    • B.

      The aircraft is a pilotless drone or missile

    • C.

      The aircraft is declaring a military emergency

    • D.

      It is requested by the radar operator to identify the aircraft position

    Correct Answer
    B. The aircraft is a pilotless drone or missile
    Explanation
    The presence of an X pulse in a selective identification feature code train indicates that the aircraft is a pilotless drone or missile. This is because the X pulse is specifically associated with pilotless drones or missiles, and is used as a means of identification in radar systems.

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  • 16. 

    Which selective identification feature special response explains a 7500 reply?

    • A.

      Communication failure

    • B.

      Military emergency

    • C.

      Engine failure

    • D.

      Hijacking

    Correct Answer
    D. Hijacking
    Explanation
    The special response that explains a 7500 reply is hijacking. When an aircraft transmits the code 7500, it is indicating that it has been hijacked or is under threat of hijacking. This code is used as a selective identification feature to alert air traffic control and other aircraft of the emergency situation.

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  • 17. 

    What is the AN/UPM–155 radar test set capable of testing?

    • A.

      Interrogators and associated components

    • B.

      Radar antenna orientation

    • C.

      Radar jamming strength

    • D.

      Radar receivers

    Correct Answer
    A. Interrogators and associated components
    Explanation
    The AN/UPM-155 radar test set is capable of testing interrogators and associated components. This means that it can assess the functionality and performance of the systems used for communication and identification purposes in radar systems. It can verify the proper functioning of these components and ensure that they are able to accurately interrogate and receive responses from other radar systems.

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  • 18. 

    What factor determines the spacing of the sidebands in an amplitude modulated signal?

    • A.

      Amplitude of the modulating signal

    • B.

      Frequency of the modulating signal

    • C.

      Amplitude of the carrier signal

    • D.

      Frequency of the carrier signal

    Correct Answer
    B. Frequency of the modulating signal
    Explanation
    The spacing of the sidebands in an amplitude modulated signal is determined by the frequency of the modulating signal. In amplitude modulation, the modulating signal is used to vary the amplitude of the carrier signal. This variation creates sidebands, which are additional frequencies that are symmetrically spaced around the carrier frequency. The spacing between these sidebands is directly related to the frequency of the modulating signal. Therefore, the frequency of the modulating signal is the factor that determines the spacing of the sidebands in an amplitude modulated signal.

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  • 19. 

    In frequency modulation, the amount of oscillator frequency change is

    • A.

      Inversely proportional to the amplitude of the modulating signal

    • B.

      Directly proportional to the amplitude of the modulating signal

    • C.

      Inversely proportional to the phase of the modulating signal

    • D.

      Directly proportional to the phase of the modulating signal

    Correct Answer
    B. Directly proportional to the amplitude of the modulating signal
    Explanation
    In frequency modulation, the amount of oscillator frequency change is directly proportional to the amplitude of the modulating signal. This means that as the amplitude of the modulating signal increases, the frequency of the oscillator also increases, and vice versa. This relationship allows for the encoding and transmission of information in the form of variations in frequency.

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  • 20. 

    In phase modulation, the carrier’s

    • A.

      Phase shifts at the rate of the modulating signal

    • B.

      Phase shifts with the phase of the modulating signal

    • C.

      Amplitude shifts at the rate of the modulating signal

    • D.

      Amplitude shifts with the phase of the modulating signal

    Correct Answer
    A. Phase shifts at the rate of the modulating signal
    Explanation
    In phase modulation, the phase of the carrier signal shifts at the rate of the modulating signal. This means that the instantaneous phase of the carrier signal changes according to the variations in the modulating signal. The amplitude of the carrier signal remains constant, but the phase is modified to represent the information contained in the modulating signal. This allows for the encoding and transmission of data in the form of phase variations in the carrier signal.

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  • 21. 

    What size bit combinations are allowed when using 16–phase shift keying?

    • A.

      2 bit

    • B.

      3 bit

    • C.

      4 bit

    • D.

      5 bit

    Correct Answer
    C. 4 bit
    Explanation
    16-phase shift keying allows for 4 bit combinations. This means that each symbol in the transmission represents 4 bits of information. With 4 bit combinations, a total of 16 different symbols can be transmitted, each representing a different combination of 4 bits.

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  • 22. 

    How is the parity bit used in asynchronous transmission?

    • A.

      By the receiving device to verify that the transmission was received correctly

    • B.

      By the transmitting device to verify that the transmission was transmitted correctly

    • C.

      By the modulator device to verify that the intelligence signal was received correctly

    • D.

      By the band limiting device to verify that the output signal was transmitted correctly

    Correct Answer
    A. By the receiving device to verify that the transmission was received correctly
    Explanation
    The parity bit is used by the receiving device to verify that the transmission was received correctly. The parity bit is an extra bit added to a binary code to detect errors in transmission. It is calculated based on the number of 1s in the data being transmitted. The receiving device checks the parity bit to ensure that the number of 1s in the received data matches the expected parity. If there is a mismatch, it indicates that an error occurred during transmission. Therefore, the receiving device uses the parity bit to verify the accuracy of the received transmission.

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  • 23. 

    How does synchronous transmission reduce the overhead costs of data transmission?

    • A.

      Communicates in parallel format

    • B.

      Blocks many characters together for transmission

    • C.

      Eliminates the control bits, so more message data can be sent

    • D.

      Uses low cost equipment to support synchronous transmission

    Correct Answer
    B. Blocks many characters together for transmission
    Explanation
    Synchronous transmission reduces the overhead costs of data transmission by blocking many characters together for transmission. This means that multiple characters are sent as a single unit, reducing the number of start and stop bits needed for each character. By reducing the number of control bits required, more message data can be sent in a shorter amount of time, resulting in lower overhead costs.

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  • 24. 

    When using forward error control as a method of error correction, where does error correction take place?

    • A.

      Receiving end

    • B.

      In the oscillator

    • C.

      Transmitting end

    • D.

      In the primary buffers

    Correct Answer
    A. Receiving end
    Explanation
    In forward error control, error correction takes place at the receiving end. This means that when data is transmitted, it may contain errors, and the receiving device is responsible for detecting and correcting these errors. This can be done through various techniques such as error detection codes or error correction codes. By performing error correction at the receiving end, the integrity and accuracy of the transmitted data can be ensured.

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  • 25. 

    Which statement describes an advantage of using fiber optic cable?

    • A.

      The easy tap-ability of fiber optic cables reduces security risks

    • B.

      Fiber optic cable has a higher attenuation than coaxial cable

    • C.

      Electromagnetic fields do not affect fiber optic cables

    • D.

      Nuclear radiation does not affect fiber optic cable

    Correct Answer
    C. Electromagnetic fields do not affect fiber optic cables
    Explanation
    Fiber optic cables are not affected by electromagnetic fields. This is because they use light signals to transmit data, rather than electrical signals. Unlike copper-based cables, which can be affected by electromagnetic interference, fiber optic cables are immune to such interference. This makes them more reliable and less susceptible to disruptions in signal quality.

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  • 26. 

    Which statement describes a security feature of using fiber optic cable?

    • A.

      Easy to encrypt data

    • B.

      Low signal attenuation

    • C.

      Virtually impossible to tap a fiber optic cable unnoticed

    • D.

      Fiber optic cables are considerably smaller than metallic cable

    Correct Answer
    C. Virtually impossible to tap a fiber optic cable unnoticed
    Explanation
    The correct answer is "Virtually impossible to tap a fiber optic cable unnoticed." This is because fiber optic cables transmit data using light signals through glass or plastic fibers, making it extremely difficult for hackers to intercept or tap into the cable without being detected. Unlike traditional metallic cables, fiber optic cables do not emit electromagnetic signals that can be easily intercepted, making them highly secure for transmitting sensitive information.

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  • 27. 

    Most fiber optic links use infrared light and consist of what frequency range?

    • A.

      400 to 750 nm

    • B.

      750 to 1500 nm

    • C.

      400 to 750 mm

    • D.

      750 to 1500 mm

    Correct Answer
    B. 750 to 1500 nm
    Explanation
    Fiber optic links use infrared light because it has a longer wavelength and can travel long distances without significant loss of signal. The frequency range of 750 to 1500 nm falls within the infrared spectrum, making it suitable for transmitting data through fiber optic cables. The other options, 400 to 750 nm and 400 to 750 mm, are not within the correct frequency range for fiber optic links.

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  • 28. 

    When considering light wave propagation, what is the name of the angle between the normal in the first material and the ray that is bounced back in the first material?

    • A.

      Angle of refraction

    • B.

      Angle of incidence

    • C.

      Angle of reflection

    • D.

      Critical angle

    Correct Answer
    C. Angle of reflection
    Explanation
    The angle between the normal in the first material and the ray that is bounced back in the first material is called the angle of reflection.

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  • 29. 

    What is the principle on which fiber optics work?

    • A.

      Total internal reflection

    • B.

      Refraction of light

    • C.

      Light wavelengths

    • D.

      Rays of incidence

    Correct Answer
    A. Total internal reflection
    Explanation
    Fiber optics work based on the principle of total internal reflection. This principle states that when light travels from a medium with a higher refractive index to a medium with a lower refractive index, it can be completely reflected back instead of being refracted. In fiber optics, light signals are transmitted through a core made of a material with a higher refractive index surrounded by a cladding with a lower refractive index. This causes the light to bounce off the walls of the core, allowing it to travel long distances without significant loss of signal strength.

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  • 30. 

    What occurs because of imperfections in an optical fiber’s basic structure?

    • A.

      Absorption

    • B.

      Scattering

    • C.

      Reflection

    • D.

      Dispersion

    Correct Answer
    B. Scattering
    Explanation
    Imperfections in an optical fiber's basic structure cause scattering. Scattering refers to the phenomenon where light rays traveling through the fiber get redirected in different directions due to these imperfections. This can result in the loss of signal strength and degradation of the transmitted data.

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  • 31. 

    What is reduced through the use of index matching fluids on fiber optic connectors?

    • A.

      Macrobends

    • B.

      Bandwidths

    • C.

      Fresnal reflection

    • D.

      Spectral attenuation

    Correct Answer
    C. Fresnal reflection
    Explanation
    Index matching fluids are used on fiber optic connectors to reduce Fresnel reflection. When light passes from a medium with a high refractive index to a medium with a low refractive index, a portion of the light is reflected back. This reflection can cause signal loss and degrade the performance of the fiber optic system. Index matching fluids, such as gel or oil, are applied to minimize the refractive index difference between the connector and the fiber, reducing the amount of reflection and improving the overall efficiency of the system.

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  • 32. 

    What is the most useful way to classify fiber optic cable?

    • A.

      Fiber material and number of fibers

    • B.

      Buffer type and application method

    • C.

      Numerical aperture and cable elements

    • D.

      Refractive index profile and number of modes

    Correct Answer
    D. Refractive index profile and number of modes
    Explanation
    The most useful way to classify fiber optic cable is by considering its refractive index profile and the number of modes it supports. The refractive index profile determines how light propagates through the fiber, while the number of modes refers to the number of different paths that light can take within the fiber. These characteristics are crucial in determining the performance and capabilities of the fiber optic cable, making them the most relevant factors for classification.

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  • 33. 

    Which feature of the Fluke 8025A multimeter do you use to select various measurement functions?

    • A.

      Circuit jacks

    • B.

      Rotary switch

    • C.

      Range pushbutton

    • D.

      Touch-hold pushbutton

    Correct Answer
    B. Rotary switch
    Explanation
    The rotary switch is used to select various measurement functions on the Fluke 8025A multimeter. This switch allows the user to easily switch between different modes, such as voltage, current, resistance, and continuity. By turning the rotary switch to the desired function, the user can quickly and accurately measure different electrical quantities.

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  • 34. 

    Which current range on the Fluke 8025A do you select to measure 250 milliamps alternating current (AC)?

    • A.

      Microamps direct current (DC)

    • B.

      Microamps AC

    • C.

      Milliamps/amp DC

    • D.

      Milliamps/amp AC

    Correct Answer
    D. Milliamps/amp AC
    Explanation
    To measure 250 milliamps alternating current (AC) on the Fluke 8025A, you would select the "Milliamps/amp AC" current range. This range is specifically designed to measure AC current in milliamps, making it the appropriate choice for this measurement.

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  • 35. 

    What is caused by low-insulation resistance between conductors?

    • A.

      High-attenuation, crosstalk, and noise

    • B.

      Fresnel reflection, dispersion, and scattering

    • C.

      High-impedance, capacitance, and rectification

    • D.

      Low-attenuation, electromagnetic immunity, and absorption

    Correct Answer
    A. High-attenuation, crosstalk, and noise
    Explanation
    Low-insulation resistance between conductors can cause high-attenuation, crosstalk, and noise. When the insulation resistance is low, it means that there is a leakage of current between the conductors. This leakage can lead to the attenuation of the signal, causing it to weaken or lose strength. Additionally, the leakage current can interfere with other nearby conductors, resulting in crosstalk, where signals from one conductor are unintentionally picked up by another. This can introduce unwanted noise into the system, further degrading the signal quality.

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  • 36. 

    When will insulation resistance increases?

    • A.

      Length of insulation increases

    • B.

      Area of the conductor increases

    • C.

      Thickness of the insulating material increases

    • D.

      Thickness and length of insulating material increases

    Correct Answer
    C. Thickness of the insulating material increases
    Explanation
    Insulation resistance increases when the thickness of the insulating material increases. This is because a thicker insulating material provides a greater barrier for the flow of electric current, reducing the chances of leakage or short-circuits. As a result, the resistance to the flow of current through the insulation increases, leading to higher insulation resistance.

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  • 37. 

    When using the AN/PSM–2 megger, how do you apply the correct regulated output voltage?

    • A.

      Turn the hand-crank until an arc is present

    • B.

      Turn the hand-crank until the needle set has stopped moving

    • C.

      Turn the hand-crank and monitor the megger’s output with another meter

    • D.

      Turn the hand-crank at a rate to keep the indicator lights at a steady glow

    Correct Answer
    D. Turn the hand-crank at a rate to keep the indicator lights at a steady glow
    Explanation
    The correct answer states that when using the AN/PSM-2 megger, the correct way to apply the regulated output voltage is to turn the hand-crank at a rate to keep the indicator lights at a steady glow. This implies that the indicator lights on the megger are used as a reference to determine the correct voltage output. By keeping the lights at a steady glow, it ensures that the voltage is regulated and maintained at the desired level.

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  • 38. 

    What type of megohmmeter do you use on paper insulated conductor cable?

    • A.

      500 volt

    • B.

      1000 volt

    • C.

      1500 volt

    • D.

      2500 volt

    Correct Answer
    A. 500 volt
    Explanation
    The correct answer is 500 volt. When testing paper insulated conductor cable, a megohmmeter with a voltage rating of 500 volts is typically used. This voltage is sufficient to measure the insulation resistance of the cable without causing any damage to the paper insulation. Higher voltage ratings may be used for different types of cables, but for paper insulated conductor cables, a 500 volt megohmmeter is appropriate.

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  • 39. 

    How many probes are normally used for an earth ground tester?

    • A.

      2

    • B.

      3

    • C.

      4

    • D.

      5

    Correct Answer
    B. 3
    Explanation
    An earth ground tester typically uses 3 probes. These probes are used to measure the resistance between the ground and the earth electrode, ensuring that the grounding system is functioning properly. The use of 3 probes allows for a more accurate measurement, as it provides a better representation of the overall resistance of the system.

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  • 40. 

    What is the earth ground standard for communications facilities?

    • A.

      10 ohms or less

    • B.

      10 ohms or more

    • C.

      25 ohms or less

    • D.

      25 ohms or more

    Correct Answer
    A. 10 ohms or less
    Explanation
    The earth ground standard for communications facilities is 10 ohms or less. This means that the resistance between the earth ground and the facility should be 10 ohms or lower. This is important for ensuring proper grounding and preventing electrical hazards. A lower resistance allows for better dissipation of electrical currents and helps protect against power surges and lightning strikes.

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  • 41. 

    Which probe does not need to actually make contact with the circuit under test?

    • A.

      Current probe

    • B.

      Passive 1:1 probe

    • C.

      Active field effect transistor probe

    • D.

      Passive divider, 10:1 probe

    Correct Answer
    A. Current probe
    Explanation
    A current probe does not need to make actual contact with the circuit under test because it uses a non-contact method to measure the current flowing through a conductor. It works by sensing the magnetic field generated by the current and converting it into a measurable signal. This allows for safe and non-intrusive measurements, especially in high voltage or high-frequency applications, where direct contact may not be feasible or safe.

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  • 42. 

    Sampled data points are stored in the memory of a digital storage oscilloscope as

    • A.

      Sequential records

    • B.

      Waveform points

    • C.

      Record lengths

    • D.

      Record points

    Correct Answer
    B. Waveform points
    Explanation
    In a digital storage oscilloscope, sampled data points are stored as waveform points. These points represent the amplitude of the waveform at specific time intervals. Storing the data as waveform points allows for accurate representation and analysis of the waveform shape and characteristics. Sequential records, record lengths, and record points are not the correct terms used to describe the storage of sampled data points in a digital storage oscilloscope.

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  • 43. 

    What is the frequency range of an audio signal generator?

    • A.

      10 Hz to 10 kHz

    • B.

      20 Hz to 20 kHz

    • C.

      10 kHz to 10GHz

    • D.

      20 kHz to 35 MHz

    Correct Answer
    B. 20 Hz to 20 kHz
    Explanation
    The frequency range of an audio signal generator is typically between 20 Hz and 20 kHz. This range covers the audible frequencies that humans can hear, with 20 Hz being the lowest frequency and 20 kHz being the highest frequency. Audio signal generators are commonly used in audio testing and equipment calibration.

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  • 44. 

    Which one of these is not an application of a radio frequency generator?

    • A.

      Verifying transmitter frequencies

    • B.

      Troubleshooting receivers

    • C.

      Checking antenna systems

    • D.

      Aligning galvanometers

    Correct Answer
    D. Aligning galvanometers
    Explanation
    Aligning galvanometers is not an application of a radio frequency generator. A radio frequency generator is used for tasks such as verifying transmitter frequencies, troubleshooting receivers, and checking antenna systems. However, aligning galvanometers is a separate task that involves adjusting and calibrating the position of galvanometers, which are devices used to measure small electrical currents. This task does not require the use of a radio frequency generator.

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  • 45. 

    How is a radio frequency generator used?

    • A.

      Monitor odd harmonics

    • B.

      Align telemetry receivers

    • C.

      Modulate subcarrier oscillators

    • D.

      Check galvanometer frequency response

    Correct Answer
    B. Align telemetry receivers
    Explanation
    A radio frequency generator is used to align telemetry receivers. This means that it is used to adjust and calibrate the receivers so that they can accurately receive and interpret the telemetry signals being transmitted. Telemetry receivers are commonly used in various industries such as telecommunications, aerospace, and medicine to collect data remotely, so it is important to ensure that they are properly aligned for optimal performance.

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  • 46. 

    What does a power reading that uses the abbreviation dBm indicate?

    • A.

      Ratio of decibels relative to a 1-milliwatt standard

    • B.

      Ratio of decibels relative to a 1-megawatt standard

    • C.

      Actual power level expressed in milliwatts

    • D.

      Actual power level expressed in megawatts

    Correct Answer
    A. Ratio of decibels relative to a 1-milliwatt standard
    Explanation
    A power reading that uses the abbreviation dBm indicates the ratio of decibels relative to a 1-milliwatt standard. dBm is a unit of power measurement commonly used in telecommunications and electronics. It represents the power level in decibels (dB) compared to a reference power of 1 milliwatt (mW). This measurement allows for a standardized and easily comparable way to express power levels in various devices and systems.

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  • 47. 

    If someone says, “we doubled our transmitter power;” how much is the gain in dB?

    • A.

      3 dB

    • B.

      6 dB

    • C.

      9 dB

    • D.

      12 dB

    Correct Answer
    A. 3 dB
    Explanation
    When someone says "we doubled our transmitter power," it means that the power has increased by a factor of 2. In terms of decibels (dB), a doubling of power corresponds to a gain of 3 dB. This is because the dB scale is logarithmic, and a gain of 3 dB represents a doubling of power. Therefore, the correct answer is 3 dB.

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  • 48. 

    The measurable frequency and power ranges of the HP 436A power meter system are determined by the

    • A.

      Digital display

    • B.

      Selected sensor

    • C.

      Power meter

    • D.

      Interface

    Correct Answer
    B. Selected sensor
    Explanation
    The measurable frequency and power ranges of the HP 436A power meter system are determined by the selected sensor. Different sensors have different capabilities and specifications, including the frequency range they can measure and the power range they can handle. Therefore, the specific sensor chosen for use with the power meter system will determine the frequency and power ranges that can be measured accurately.

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  • 49. 

    Which measurement is not made with a spectrum analyzer?

    • A.

      Frequency stability

    • B.

      Peak-peak voltage

    • C.

      Amplitude modulation

    • D.

      Subcarrier oscillator outputs

    Correct Answer
    B. Peak-peak voltage
    Explanation
    A spectrum analyzer is a device used to measure and display the frequency spectrum of a signal. It is primarily used to analyze the frequency content of a signal and identify its various components. Peak-peak voltage, on the other hand, is a measurement of the difference between the maximum and minimum voltage levels in an AC signal. While a spectrum analyzer can provide information about the amplitude of different frequency components, it is not specifically designed to directly measure peak-peak voltage. Therefore, peak-peak voltage is not typically measured with a spectrum analyzer.

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  • 50. 

    Which electronic counter measurement represents the average bit-to-bit time of an input signal?

    • A.

      Period

    • B.

      Scaling

    • C.

      Frequency

    • D.

      Time interval

    Correct Answer
    A. Period
    Explanation
    The correct answer is "Period". In electronic counter measurements, the period represents the average bit-to-bit time of an input signal. It is the time taken for one complete cycle of a repetitive waveform. By measuring the period, we can determine the average time between each bit in the signal, which is useful in various applications such as data communication and signal processing.

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Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 18, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Mar 17, 2014
    Quiz Created by
    Matthoef
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