VDV Fiber Optics 4

Question 1

What does an 'APC' fiber connector end-face polish provide compared to a 'UPC' polish?

Accepted Answer

Higher return loss due to its angled 8-degree end-face

Answer

APC (Angled Physical Contact) connectors have an 8-degree angled end-face that reflects light away from the core, achieving return loss >60 dB versus ~55 dB for UPC.

Question 2

Which parameter measured in dB represents the total allowed signal loss for a fiber optic link from source to receiver?

Accepted Answer

Optical power budget (loss budget)

Answer

The optical power (loss) budget is the difference between transmitter output power and receiver sensitivity, defining the maximum allowable link loss.

Question 3

What causes 'Rayleigh scattering' loss in optical fiber?

Accepted Answer

Microscopic density variations in the glass material

Answer

Rayleigh scattering occurs when light interacts with tiny density fluctuations inherent in the glass structure, and is the dominant loss mechanism at shorter wavelengths.

Question 4

A VDV technician must install fiber in a plenum space. Which cable type must be used?

Accepted Answer

OFNP (Plenum rated) fiber

Answer

OFNP (Optical Fiber Nonconductive Plenum) cables are required in plenum spaces because they have low-smoke, flame-retardant jackets that meet NEC Article 770 requirements.

Question 5

What is the typical core/cladding diameter of standard 62.5 µm multimode fiber?

Accepted Answer

62.5/125 µm

Answer

Standard 62.5 µm multimode fiber has a 62.5 µm core and 125 µm cladding diameter, making it compatible with LED-based transmitters.

(VDV) Voice Data Video Technician Certified Practice Test

(VDV) Voice Data Video Technician Certified Practice Test

VDV Fiber Optics 4