Practice Test Geeks(CWT) Certified Wireless Technician Practice Test
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Power over Ethernet (PoE) & Cabling Infrastructure Flashcards

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

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  1. Which IEEE standard originally defined Power over Ethernet (PoE), delivering up to 15.4W per port?

    Answer: IEEE 802.3af

    IEEE 802.3af was the first IEEE standard to define PoE, specifying up to 15.4W of power per port at the PSE.

  2. What is the maximum power output per port at the PSE specified by IEEE 802.3at (PoE+)?

    Answer: 30 watts

    IEEE 802.3at (PoE+) doubled the original PoE power ceiling, specifying a maximum of 30W per port at the power sourcing equipment.

  3. Under IEEE 802.3af, what maximum power is guaranteed at the powered device (PD) after accounting for cable losses?

    Answer: 12.95 watts

    After resistive losses in the cable, a PD is guaranteed a maximum of 12.95W, even though the PSE outputs up to 15.4W.

  4. Which device is used to add PoE capability to an existing non-PoE switch infrastructure?

    Answer: PoE midspan injector

    A PoE midspan injector sits between a non-PoE switch and the PD, injecting DC power onto the Ethernet cable without requiring a PoE-capable switch.

  5. What is the minimum recommended cable category for IEEE 802.3at (PoE+) installations?

    Answer: CAT5e

    CAT5e is the minimum recommended cabling for PoE+ deployments, providing adequate conductor gauge and insulation to minimize resistive power losses.

  6. What is the maximum standard cable run length permitted for PoE power delivery?

    Answer: 100 meters

    PoE power delivery follows the same 100-meter (328 ft) maximum cable run as standard Ethernet, beyond which voltage drop and data signal degradation become problematic.

  7. How does a PoE Power Sourcing Equipment (PSE) detect a valid Powered Device (PD) before applying full power?

    Answer: It applies a low-voltage DC signature detection signal

    A PSE applies a low-voltage DC detection signal to identify the characteristic resistive signature (approximately 25kΩ) of a valid PD before committing full power.