QUIZ BY JIM HAYES
1. In a fiber optic network design, the loss budget for the cable
plant and the power budget for the fiber optic link for the
application are both 5 decibels (dB). Will it work?
A. Whoa! No margin at all? That’s asking for trouble.
B. Sure, both the loss budget and the power budget are
C. Sure, manufacturers usually have extra margin in
their power budget estimates.
D. Maybe, try it anyway. What’s there to lose?
2. You need 10 kilometers (km) of cable for the outside plant link
you are installing, and you have three splice points. You use
an optical time-domain reflectometer (OTDR) on the spool of
cable you have and find it is exactly 10 km. Is that enough?
A. No, the three splice points will use up several
hundred meters of cable.
B. No, the OTDR measures fiber length that is longer
than the cable by 1 percent.
C. No, you should plan on having 12–15 percent more
cable than the length anyway.
D. No, for all of the above reasons.
3. You tested the loss of a fiber optic cable plant at 2. 15 dB,
but the loss budget for that cable was only 2.00 dB.
What do you do?
A. Fail the cable and look for ways to improve the loss.
B. Inspect and clean the connectors, and test again.
C. Pass the cable anyway; it’s pretty close.
D. Don’t worry about it; nobody ever reads test reports.
4. After you cleaned the connectors on that cable plant, the
loss dropped to 2.05 dB. That’s within the margin of error
of the measurement, so it is OK to pass that cable.
5. In an electronics upgrade to an old fiber optic cable plant
that uses 62.5/125 micron fiber, you realize you only have
50/125 micron patchcords. What can you do?
A. Go ahead and use them; they’re close enough in size.
B. Just keep the 50/125 patchcords short to reduce the loss.
C. Check the power budget because you might have
D. Order the right patchcords as soon as possible.
6. At the job site, you realize you are terminating multimode
fiber with the adhesive/polish method but only have single-mode connectors. Is that OK?
A. Yes, all ceramic ferrule connectors are identical.
B. Sure, single-mode connectors are made more
C. No way, single-mode connectors are not made
for hand polishing.
D. Maybe, single-mode connectors have a smaller
hole for the fiber.
7. As you prepare to terminate these connectors, you notice
the adhesive you have been using for a while is
out of date by almost a year. Do you use it anyway?
A. No way, it’s too critical to take that risk.
B. Why not? There’s always some time beyond the
C. Sure, it worked on the last batch of connectors
a week ago.
D. Yeah, you can always come back and fix any that fail.
8. That 20-km cable plant you are testing with an OTDR shows
about a third of all the splices are gainers. What can you do?
A. Nothing, that’s below average for the percentage
B. Test in the opposite direction to average the splice
loss. Gainers are not a reason to fail tests.
C. Ignore it. Gainers are just an OTDR phenomenon.
D. Replace the cable. The fibers are bad.
9. You are estimating a fiber optic cable plant for a bid.
How many extra components do you figure into the price?
10. Over the course of the day, you worry because loss test
results on a high fiber count cable keep getting higher.
What could cause this?
A. Improper cleaning of connectors before testing
B. Test source battery running down
C. Wear and tear on the reference test cables
D. Any or all of the above
HA YES is a VDV writer and educator and the president of the Fiber Optic Association. Find him at
When designing, building, testing or operating a fiber optic network, is “close enough” good enough?
ANSWERS ARE ON PAGE 95. TO TAKE THE QUIZ ELECTRONICALLY, VISIT