RCDD Optical Fiber Systems and Testing 3

Question 1

What does an OTDR 'ghost' event indicate?

Accepted Answer

A false reflection caused by high-reflectance events creating phantom signals further down the trace

Answer

A fiber break at the far end of the cable

Answer

A damaged OTDR launch cord

Answer

A section of fiber with high attenuation

Question 2

Why is a launch cable (also called a launch fiber or mandrel) used when performing OTDR testing?

Accepted Answer

To allow the OTDR to fully recover from the initial blind zone before measuring the first connector on the fiber under test

Answer

To extend the OTDR's range to longer distances

Answer

To calibrate the OTDR's wavelength output before testing

Answer

To prevent laser light from entering the work area during testing

Question 3

What is 'macrobending loss' in optical fiber?

Accepted Answer

Loss caused by bending the fiber cable below its minimum bend radius, causing light to escape the core

Answer

Loss due to microscopic imperfections in the fiber core during manufacturing

Answer

Dispersion caused by multiple modes traveling at different speeds

Answer

Attenuation caused by hydroxyl ion absorption at 1383 nm

Question 4

Which standard defines the testing requirements for installed optical fiber cabling systems including insertion loss and return loss?

Accepted Answer

ANSI/TIA-526-14 (multimode) and ANSI/TIA-526-7 (single-mode)

Answer

ANSI/TIA-568 only

Answer

IEEE 802.3 only

Answer

ITU-T G.652 only

Question 5

What is 'modal bandwidth' and why does it matter for multimode fiber?

Accepted Answer

The frequency range over which a multimode fiber can transmit; higher modal bandwidth supports faster data rates over longer distances

Answer

The range of wavelengths supported by multimode fiber

Answer

The number of channels that can be wavelength-multiplexed on a fiber

Answer

The maximum launch power that prevents stimulated Raman scattering

Question 6

What safety practice is mandatory when working with active optical fiber systems?

Accepted Answer

Never look into an active fiber end or connector without using an appropriate optical power meter or fiber inspection scope

Answer

Always wear grounding straps when handling fiber connectors

Answer

Deactivate the entire network before cleaning any fiber connectors

Answer

Use only APC connectors on all active systems