Practice Test Geeks(VDV) Voice Data Video Technician Certified Practice Test
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Mixed Deck — All VDV Topics Flashcards

100 cards from real VDV practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 20 Mixed Deck — All VDV Topics flashcards as text

  1. A technician suspects a ground loop is causing hum bars on a video display. Which test confirms a ground potential difference between equipment?

    Answer: Measure the AC voltage between the chassis grounds of the two connected devices with a multimeter

    Measuring AC voltage between the chassis grounds of two devices reveals a ground potential difference, which is the root cause of hum bars induced by ground loop current.

  2. A technician needs to extend a Cat6 run beyond the 90-meter horizontal limit. What is the correct solution under TIA-568?

    Answer: Install an intermediate distribution frame (IDF) with an active switch to restart the segment

    TIA-568 limits horizontal copper runs to 90 meters; longer distances require an active network switch at an IDF to regenerate the signal for a new 90-meter segment.

  3. What is the recommended test method for verifying proper operation of a PoE (Power over Ethernet) installation?

    Answer: PoE tester that verifies voltage, current, and power classification

    A dedicated PoE tester verifies that the correct voltage and current are present and that the PSE correctly identifies the PD power class per IEEE 802.3af/at/bt.

  4. Which of the following is a key advantage of using pre-terminated fiber trunk cables in a data center installation?

    Answer: They reduce installation time and minimize splice loss by factory-polishing connectors

    Factory pre-terminated trunks arrive with precisely polished connectors and factory-tested performance, significantly reducing on-site labor and providing consistent, low-loss terminations compared to field work.

  5. A rack is running hot and equipment is shutting down due to thermal protection. What is the FIRST corrective action a technician should take?

    Answer: Add a rack-mount exhaust fan and verify adequate front-to-back airflow

    Installing a rack exhaust fan and ensuring proper front-to-back airflow is the most immediate and effective solution for rack thermal issues.

  6. When terminating an RJ-45 connector for a VoIP phone installation, which wiring standard is most commonly used in the United States?

    Answer: Either T568A or T568B, but consistently throughout the installation

    Both T568A and T568B are acceptable, but the same standard must be used consistently on both ends of every cable in the installation.

  7. A VDV certified professional is asked to provide services outside their scope of competence. The CORRECT ethical response is to:

    Answer: Decline and refer to a qualified professional

    Ethical practice requires professionals to work within their scope of competence. Accepting work beyond one's qualifications can lead to substandard results and potential harm. Referring to qualified professionals ensures proper service delivery.

  8. Which fiber optic connector type uses a push-pull latching mechanism and is common in data center applications?

    Answer: LC connector

    LC (Lucent Connector) uses a push-pull latch similar to an RJ-45 and has a small form factor suited for high-density data center use.

  9. During coaxial cable testing, a return loss of 20 dB is measured. What does this indicate?

    Answer: Acceptable impedance matching with minimal reflections

    A return loss of 20 dB means only 1% of the signal is reflected, indicating good impedance matching in the cable system.

  10. What does EIRP stand for in wireless system design?

    Answer: Effective Isotropic Radiated Power

    EIRP (Effective Isotropic Radiated Power) is the total power radiated in a single direction, combining transmitter output power and antenna gain.

  11. Why is it important to avoid ground loops in telecommunications bonding systems?

    Answer: Ground loops can induce noise and interference into telecommunications circuits

    Ground loops create paths for circulating currents that can induce noise and interference into telecommunications circuits, degrading signal quality.

  12. What is the maximum transmission power typically allowed for 2.4 GHz Wi-Fi in the United States per FCC Part 15 rules?

    Answer: 100 mW (20 dBm)

    FCC Part 15 limits 2.4 GHz WLAN transmitter output to 1 W (30 dBm), but with antenna gain the EIRP is limited to 4 W; typical device limits are 100 mW (20 dBm).

  13. A technician is certifying a Cat6A cable channel and the test fails for 'alien crosstalk' (AXT). What is the most effective corrective action?

    Answer: Increase physical separation between parallel cable runs or use F/UTP shielded cable

    Alien crosstalk occurs between adjacent cables; increasing separation, using bundling best practices, or switching to shielded F/UTP cable are the recognized remedies.

  14. Which wireless protocol operates in the 900 MHz band and is commonly used for long-range IoT sensor networks?

    Answer: LoRaWAN

    LoRaWAN uses 915 MHz (in the US) and is designed for low-power, long-range IoT applications spanning many miles.

  15. What is the correct term for the point in a structured cabling system where outside plant cabling transitions to inside plant cabling?

    Answer: Entrance Facility (EF)

    The Entrance Facility is where outside plant cables enter the building and connect to the inside telecommunications infrastructure.

  16. What does the term 'Tier 1' testing mean in the context of fiber optic certification per TIA-526-14-B?

    Answer: Insertion loss testing using a light source and power meter

    Tier 1 fiber testing measures insertion loss using a calibrated light source and optical power meter, providing a pass/fail result against the loss budget.

  17. What is the primary consideration when implementing changes to network infrastructure?

    Answer: Impact assessment and change management

    Impact assessment and proper change management ensure that modifications do not introduce unexpected problems or service disruptions.

  18. Which wiring standard requires that the green pair be placed on pins 1 and 2 of an 8P8C outlet?

    Answer: T568A

    T568A places the green pair (pair 3) on pins 1-2 and the orange pair (pair 2) on pins 3-6.

  19. A VDV technician is asked to install cabling in a riser between floors. Which cable jacket rating is required?

    Answer: CMR

    CMR (Communications Riser) rated cable is required for vertical runs between floors because it is designed to resist flame spread in vertical shafts without the full plenum rating.

  20. A cable TV technician finds that picture quality degrades only during rain. Which component is MOST likely at fault?

    Answer: A loose or corroded F-connector allowing moisture ingress

    Rain-related intermittent signal degradation is a classic symptom of moisture getting into a poorly sealed or corroded coaxial connector.