PROGRESSION: FIELD TECH III – IV FINAL ACTUAL EXAM
QUESTIONS AND VERIFIED DETAILED ANSWERS UPDATED 2026
(GRADED A+)
Questions 1–50: Fiber Optics Fundamentals
Question 1:
What is the typical wavelength used for single-mode fiber optic
transmission in telecommunications?
A) 850 nm
B) 1300 nm
C) 1310 nm and 1550 nm
D) 1625 nm
VERIFIED ANSWER: C) 1310 nm and 1550 nm
Rationale: Single-mode fiber typically operates at 1310 nm and 1550 nm
wavelengths. 850 nm is used for multimode fiber, while 1625 nm is used
for testing and monitoring.
Question 2:
What is the maximum attenuation per kilometer for single-mode fiber at
1310 nm per industry standards?
,A) 0.1 dB/km
B) 0.4 dB/km
C) 1.0 dB/km
D) 3.0 dB/km
VERIFIED ANSWER: B) 0.4 dB/km
Rationale: Industry standards (TIA/EIA) specify maximum attenuation of
0.4 dB/km for single-mode fiber at 1310 nm and 0.3 dB/km at 1550 nm.
Question 3:
What is the core diameter of standard single-mode fiber?
A) 8–10 microns
B) 50 microns
C) 62.5 microns
D) 100 microns
VERIFIED ANSWER: A) 8–10 microns
Rationale: Single-mode fiber has a core diameter of 8–10 microns.
Multimode fiber has core diameters of 50 microns (OM3/OM4) or 62.5
microns (OM1).
Question 4:
What is the primary cause of chromatic dispersion in single-mode fiber?
,A) Multiple light paths
B) Different wavelengths traveling at different speeds
C) Fiber bending
D) Connector contamination
VERIFIED ANSWER: B) Different wavelengths traveling at different speeds
Rationale: Chromatic dispersion occurs because different wavelengths of
light travel at different speeds through the fiber, causing pulse
broadening. This limits bandwidth over long distances.
Question 5:
What type of connector is most commonly used for single-mode fiber in
telecommunications?
A) ST
B) SC
C) LC
D) FC
VERIFIED ANSWER: C) LC
Rationale: LC (Lucent Connector) is the most common connector for
single-mode fiber in telecommunications due to its small form factor and
reliable performance. SC is also common but larger.
, Question 6:
What is the typical insertion loss limit for a single-mode fusion splice?
A) 0.01 dB
B) 0.1 dB
C) 0.3 dB
D) 1.0 dB
VERIFIED ANSWER: B) 0.1 dB
Rationale: Industry standards specify maximum insertion loss of 0.1 dB
for fusion splices in single-mode fiber. Mechanical splices typically allow
up to 0.3 dB.
Question 7:
What is the purpose of an OTDR (Optical Time Domain Reflectometer)?
A) Measure optical power
B) Measure fiber length and locate faults
C) Clean fiber connectors
D) Splice fiber cables
VERIFIED ANSWER: B) Measure fiber length and locate faults
Rationale: An OTDR sends pulses of light into the fiber and analyzes
backscattered light to characterize the fiber, measure length, and locate
faults such as breaks, splices, and connectors.
QUESTIONS AND VERIFIED DETAILED ANSWERS UPDATED 2026
(GRADED A+)
Questions 1–50: Fiber Optics Fundamentals
Question 1:
What is the typical wavelength used for single-mode fiber optic
transmission in telecommunications?
A) 850 nm
B) 1300 nm
C) 1310 nm and 1550 nm
D) 1625 nm
VERIFIED ANSWER: C) 1310 nm and 1550 nm
Rationale: Single-mode fiber typically operates at 1310 nm and 1550 nm
wavelengths. 850 nm is used for multimode fiber, while 1625 nm is used
for testing and monitoring.
Question 2:
What is the maximum attenuation per kilometer for single-mode fiber at
1310 nm per industry standards?
,A) 0.1 dB/km
B) 0.4 dB/km
C) 1.0 dB/km
D) 3.0 dB/km
VERIFIED ANSWER: B) 0.4 dB/km
Rationale: Industry standards (TIA/EIA) specify maximum attenuation of
0.4 dB/km for single-mode fiber at 1310 nm and 0.3 dB/km at 1550 nm.
Question 3:
What is the core diameter of standard single-mode fiber?
A) 8–10 microns
B) 50 microns
C) 62.5 microns
D) 100 microns
VERIFIED ANSWER: A) 8–10 microns
Rationale: Single-mode fiber has a core diameter of 8–10 microns.
Multimode fiber has core diameters of 50 microns (OM3/OM4) or 62.5
microns (OM1).
Question 4:
What is the primary cause of chromatic dispersion in single-mode fiber?
,A) Multiple light paths
B) Different wavelengths traveling at different speeds
C) Fiber bending
D) Connector contamination
VERIFIED ANSWER: B) Different wavelengths traveling at different speeds
Rationale: Chromatic dispersion occurs because different wavelengths of
light travel at different speeds through the fiber, causing pulse
broadening. This limits bandwidth over long distances.
Question 5:
What type of connector is most commonly used for single-mode fiber in
telecommunications?
A) ST
B) SC
C) LC
D) FC
VERIFIED ANSWER: C) LC
Rationale: LC (Lucent Connector) is the most common connector for
single-mode fiber in telecommunications due to its small form factor and
reliable performance. SC is also common but larger.
, Question 6:
What is the typical insertion loss limit for a single-mode fusion splice?
A) 0.01 dB
B) 0.1 dB
C) 0.3 dB
D) 1.0 dB
VERIFIED ANSWER: B) 0.1 dB
Rationale: Industry standards specify maximum insertion loss of 0.1 dB
for fusion splices in single-mode fiber. Mechanical splices typically allow
up to 0.3 dB.
Question 7:
What is the purpose of an OTDR (Optical Time Domain Reflectometer)?
A) Measure optical power
B) Measure fiber length and locate faults
C) Clean fiber connectors
D) Splice fiber cables
VERIFIED ANSWER: B) Measure fiber length and locate faults
Rationale: An OTDR sends pulses of light into the fiber and analyzes
backscattered light to characterize the fiber, measure length, and locate
faults such as breaks, splices, and connectors.
