Certified Wireless Network Professional (CWNA) Quiz

70 Questions | Total Attempts: 147

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CWNA Quizzes & Trivia

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Questions and Answers
  • 1. 
    What can cause an excessively high VSWR (Voltage Standing Wave Ratio) in a WLAN RFtransmission line?
    • A. 

      Reflected direct current (DC) voltage on the main RF signal line

    • B. 

      An impedance mismatch in the RF cables and connectors

    • C. 

      Attenuation of the RF signal as it travels along the main signal path

    • D. 

      Crosstalk (inductance) between adjacent RF conductors

  • 2. 
    What word describes the bending of an RF signal as it passes through a medium of a varyingdensity from that of free space?
    • A. 

      Reflection

    • B. 

      Diffraction

    • C. 

      Refraction

    • D. 

      Diffusion

    • E. 

      Scattering

  • 3. 
    What factors influence the distance that an RF signal can be effectively received? (Choose 3)
    • A. 

      MAC layer encryption

    • B. 

      Transmitting station’s power source

    • C. 

      Free Space Path Loss

    • D. 

      Transmitting station’s output power

    • E. 

      Temperature in the Fresnel zone

    • F. 

      Receiving station’s radio sensitivity

  • 4. 
    As an RF wave propagates through space, the wave front experiences natural expansion thatreduces its signal strength in an area. What term describes the rate at which this expansionhappens?
    • A. 

      MU-MIMO

    • B. 

      Inverse square law

    • C. 

      Path spread phenomenon

    • D. 

      Fresnel zone thinning

    • E. 

      Ohm’s law

  • 5. 
    Return Loss is the decrease of forward energy in a system when some of the power is beingreflected back toward the transmitter.What will cause high return loss in an RF transmission system, including the radio, cables,connectors and antenna?
    • A. 

      A Voltage Standing Wave Ratio (VSWR) of 1:1

    • B. 

      Cross-polarization of the RF signal as it passes through the RF system

    • C. 

      An impedance mismatch between components in the RF system

    • D. 

      The use of cables longer than one meter in the RF system

    • E. 

      High output power at the transmitter and use of a low-gain antenna

  • 6. 
    What factors are taken into account when calculating the Link Budget of a point-to-point outdoorWLAN bridge link?
    • A. 

      Antenna height

    • B. 

      Transmit antenna gain

    • C. 

      Transmit power

    • D. 

      Operating frequency

  • 7. 
    A WLAN transmitter that emits a 200 mW signal is connected to a cable with 3 dB loss.If the cable is connected to an antenna with 10 dBi gain, what is the EIRP at the antenna element?
    • A. 

      10 dBm

    • B. 

      13 dBm

    • C. 

      20 dBm

    • D. 

      26 dBm

    • E. 

      30 dBm

  • 8. 
    In a long-distance RF link, what statement about Fade Margin is true?
    • A. 

      The Fade Margin of a long-distance radio link should be equivalent to the receiver’s antenna gain.

    • B. 

      A Fade Margin is unnecessary on a long-distance RF link if more than 80% of the first Fresnel zone is clear of obstructions

    • C. 

      Fade Margin is an additional pad of signal strength designed into the RF system to compensate for unpredictable signal fading.

    • D. 

      The Fade Margin is a measurement of signal loss through free space, and is a function of frequency and distance.

  • 9. 
    Which unit of measurement is an absolute unit that is used to quantify power levels on a linearscale?
    • A. 

      DBm

    • B. 

      W

    • C. 

      dB

    • D. 

      mW

    • E. 

      VSWR

  • 10. 
    An 802.11 WLAN transmitter that emits a 50 mW signal is connected to a cable with 3 dB of loss.The cable is connected to an antenna with 16 dBi of gain.What is the EIRP power output?
    • A. 

      1000 mW

    • B. 

      25 mW

    • C. 

      50 mW

    • D. 

      250 mW

    • E. 

      10 mW

  • 11. 
    What is always required to establish a high quality 2.4 GHz RF link at a distance of 3 miles(5 kilometers)?
    • A. 

      Accurate Earth Bulge calculations

    • B. 

      Minimum output power level of 2 W

    • C. 

      Grid antennas at each endpoint

    • D. 

      A Fresnel Zone that is at least 60% clear of obstructions

    • E. 

      A minimum antenna gain of 11 dBi at both endpoints

  • 12. 
    What phrase defines Equivalent Isotropically Radiated Power (EIRP)?
    • A. 

      Reflected power due to an impedance mismatch in the signal path

    • B. 

      The power output from the radio into the RF cable

    • C. 

      The highest RF signal strength that is transmitted from a given antenna

    • D. 

      Power supplied from the transmission line to the antenna input

    • E. 

      The power output from the radio into the RF cable

  • 13. 
    What term describes the effect of increasing the intensity of an RF wave with an antenna byfocusing the energy in a specific direction? 
    • A. 

      Beam Compression

    • B. 

      Distributed Radiation

    • C. 

      Active Amplification

    • D. 

      Passive Gain

    • E. 

      RF Flooding

  • 14. 
    Which antenna types are commonly used by indoor Wi-Fi devices in a MIMO diversityimplementation? (Choose 2)
    • A. 

      Grid

    • B. 

      Dipole

    • C. 

      Patch

    • D. 

      Dish

    • E. 

      Sector

  • 15. 
    What phrase correctly completes the following sentence?When using WMM Power Save operation, a wireless client device ______________. 
    • A. 

      Alternates between awake and dozing, depending on its need to transmit and receive information

    • B. 

      Enters a low-power radio state until it receives a WMM PS-Poll frame from the AP

    • C. 

      Experiences higher throughput and lower latency than when operating in Active mode

    • D. 

      Powers down a subset of MIMO radio chains and transmits information at a slower data rate

    • E. 

      Buffers frames destined to the low-power AP until the AP wakes its radio and begins beaconing again

  • 16. 
    When replacing the antenna of a WLAN device with a similar antenna type that has a higherpassive gain, what antenna characteristic will decrease?
    • A. 

      Range

    • B. 

      Beam width

    • C. 

      Active gain

    • D. 

      Receive sensitivity

    • E. 

      Fresnel Zone size

    • F. 

      Fresnel Zone size

  • 17. 
    What statements about the beamwidth of an RF antenna are true? (Choose 2)
    • A. 

      The lower the gain of an antenna, the more narrow one or both beamwidths become

    • B. 

      The beamwidth patterns on an antenna polar chart indicate the point at which the RF signal stops propagating

    • C. 

      Horizontal and vertical beamwidth are calculated at the points in which the main lobe decreases power by 3 dB.

    • D. 

      Horizontal beamwidth is displayed (in degrees) on the antenna’s Azimuth Chart.

  • 18. 
    What HT technology requires MIMO support on both the transmitter and receiver?
    • A. 

      Spatial multiplexing

    • B. 

      Short guard intervals

    • C. 

      Maximal ratio combining

    • D. 

      Orthogonal Frequency Division Multiplexing

  • 19. 
    ABC Company has just purchased a 6 dBi patch antenna. After performing some tests with the 6 dBi antenna, they have concluded that more antenna gain is needed to cover their outdoor courtyard. When choosing an antenna with higher gain, what other antenna characteristic will also always change?
    • A. 

      Fresnel Zone size

    • B. 

      Beamwidth

    • C. 

      Maximum input power

    • D. 

      Impedance

    • E. 

      VSWR Ratio

  • 20. 
    AP-1 is a 3x3:2 AP. STA-3 is a 3x3:3 client. What is the maximum number of spatial streams thatcan be used for a downlink HT-OFDM transmission from AP-1 to STA-3?
    • A. 

      One spatial stream, because the definition of the AP indicates that it is capable of only one spatial stream.

    • B. 

      Three spatial streams, because the definition of the client indicates that it is capable of only three spatial streams.

    • C. 

      Two spatial streams, because the definition of the AP indicates that it is capable of only two spatial streams

    • D. 

      Three spatial streams, because the definition of the AP indicates that it is capable of only three spatial streams.

  • 21. 
    You are implementing a VHT-capable AP. Which one of the following channels is available in the 802.11ac amendment to the 802.11-2012 standard, which was not available in the standard beforethis amendment?
    • A. 

      153

    • B. 

      144

    • C. 

      161

    • D. 

      56

    • E. 

      48

  • 22. 
    You are selecting antennas for a WLAN operating in the 5 GHz frequency band. Whatspecifications should be evaluated for an antenna before it is implemented in this WLAN system?(Choose 3)
    • A. 

      802.11ad compatibility

    • B. 

      TPC support

    • C. 

      Impedance in Ohms

    • D. 

      Elevation Beamwidth

    • E. 

      Return Loss Rating

    • F. 

      Operating Frequencies

  • 23. 
    What is the intended use for the WLAN hardware known as a pole or mast mount unit?
    • A. 

      Mounting a lightning arrestor to a grounding rod

    • B. 

      Mounting an omnidirectional antenna to a mast

    • C. 

      Mounting an RF amplifier to a dipole antenna

    • D. 

      Mounting a PoE injector to a perforated radome

    • E. 

      Mounting an access point to a site survey tripod

  • 24. 
    XYZ Corporation is experiencing connectivity problems with their existing building-to-building bridge link. A concrete wall on the roof of one building is partially blocking the Fresnel Zone, and the connection is dropping many frames. The administrator moves the antenna to an area not obstructed by the concrete wall and then realizes the RF cable cannot reach the new location If an extension cable is added to move the antenna, what are the likely results?
    • A. 

      The data throughput rate will increase because VSWR will decrease.

    • B. 

      The Equivalent Isotropically Radiated Power (EIRP) will decrease.

    • C. 

      The antenna’s azimuth beamwidth will decrease.

    • D. 

      The size of the Fresnel zone will increase.

    • E. 

      The likelihood of a direct lightning strike will increase.

  • 25. 
    When using an RF splitter to connect one transceiver to sector antennas loss is incurred. What isthis loss called?
    • A. 

      Conversion loss

    • B. 

      Through loss

    • C. 

      Active loss

    • D. 

      Intentional loss