CompTIA Network+ Question C-12

A network technician must utilize multimode fiber to uplink a new networking device. Which of the following Ethernet standards could the technician utilize? (Select TWO).

A. 1000Base-LR
B. 1000Base-SR
C. 1000Base-T
D. 10GBase-LR
E. 10GBase-SR
F. 10GBase-T

Correct Answer: BE

Explanation:
1000BASE-SX is a fiber optic Gigabit Ethernet standard for operation over multi-mode fiber with a distance capability between 220 meters and 550 meters. 10Gbase-SR is a 10 Gigabit Ethernet LAN standard for operation over multi-mode fiber optic cable and short wavelength signaling.

CompTIA Network+ Question B-94

A technician is tasked with connecting a router to a DWDM. The technician connects the router to the multiplexer and confirms that there is a good signal level. However, the interface on the router will not come up. Which of the following is the MOST likely cause?

A. The wrong wavelength was demuxed from the multiplexer.
B. The SFP in the multiplexer is malfunctioning.
C. There is a dirty connector on the fiber optic cable.
D. The fiber optic cable is bent in the management tray.

Correct Answer: A

Explanation:
A multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A demultiplexer (or demux) is a device taking a single input signal and selecting one of many data-output-lines, which is connected to the single input. Since the signal going in is good, the problem must be with the signal output. If the correct wavelength was demultiplexed, the interface will be displayed on the router.

CompTIA Network+ Question A-42

A network technician has configured a point-to-point interface on a router, however, once the fiber optic cables have been run, the interface will not come up. The technician has cleaned the fiber connectors and used an optical power meter to confirm that light is passing in both directions without excessive loss. Which of the following is the MOST likely cause?

A. Distance limitation
B. Wavelength mismatch
C. cross-talk
D. EMI
E. Macro bend

Correct Answer: B

CompTIA A+ Question D-15

Which of the following cable types is LEAST affected in areas of high EMI?

A. UTP
B. Coax
C. STP
D. Fiber

Correct Answer: D

Explanation:
Fiber optic cable is not affected by electro magnetic interference because it is related to optics technology and doesn’t have parts that might be affected by EMI.