Fiber Optic Technician Practice Exam
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Answers) Plus Rationales 2026 Q&A |
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1. What is the primary function of fiber optic cable?
A. Transmit electrical signals
B. Transmit light signals
C. Store data locally
D. Amplify radio waves
Answer: B. Transmit light signals
Rationale: Fiber optics use light (photons) instead of electricity to
transmit data over long distances.
2. Which material is commonly used as the core of fiber optic cables?
A. Copper
B. Aluminum
C. Glass or plastic
D. Steel
Answer: C. Glass or plastic
Rationale: The core is made of highly transparent glass or plastic to
allow light transmission.
,3. What does cladding do in a fiber optic cable?
A. Protects outer jacket only
B. Reflects light back into the core
C. Conducts electricity
D. Amplifies signals
Answer: B. Reflects light back into the core
Rationale: Cladding keeps light signals inside the core through total
internal reflection.
4. What phenomenon allows fiber optics to transmit light efficiently?
A. Refraction loss
B. Electrical conduction
C. Total internal reflection
D. Magnetic induction
Answer: C. Total internal reflection
Rationale: Light is reflected within the core due to differences in
refractive index.
5. Which tool is used to measure optical power?
A. Multimeter
B. OTDR
C. Optical power meter
D. Voltmeter
Answer: C. Optical power meter
Rationale: It measures the strength of light signals in fiber optic
systems.
,6. What does OTDR stand for?
A. Optical Transmission Data Router
B. Optical Time Domain Reflectometer
C. Optical Testing Data Receiver
D. Output Transmission Digital Reader
Answer: B. Optical Time Domain Reflectometer
Rationale: OTDR is used to test fiber length, faults, and splices.
7. Which type of fiber is best for long-distance communication?
A. Plastic fiber
B. Multimode fiber
C. Single-mode fiber
D. Coaxial fiber
Answer: C. Single-mode fiber
Rationale: Single-mode fiber reduces signal loss over long distances.
8. What is the typical core size of single-mode fiber?
A. 50 microns
B. 62.5 microns
C. 9 microns
D. 125 microns
Answer: C. 9 microns
Rationale: Single-mode fibers have a very small core for one light path.
, 9. Which connector is commonly used in fiber optics?
A. RJ45
B. SC connector
C. USB connector
D. HDMI connector
Answer: B. SC connector
Rationale: SC connectors are widely used for fiber optic termination.
10. What is fiber attenuation?
A. Signal amplification
B. Signal loss over distance
C. Signal conversion
D. Signal reflection
Answer: B. Signal loss over distance
Rationale: Attenuation refers to weakening of light signal as it travels.
11. What causes macro-bending loss?
A. Electrical interference
B. Large physical bends in fiber
C. High voltage
D. Temperature increase
Answer: B. Large physical bends in fiber
Rationale: Sharp bends cause light to escape the core.
12. Which light source is commonly used in fiber optics?
Questions With Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the primary function of fiber optic cable?
A. Transmit electrical signals
B. Transmit light signals
C. Store data locally
D. Amplify radio waves
Answer: B. Transmit light signals
Rationale: Fiber optics use light (photons) instead of electricity to
transmit data over long distances.
2. Which material is commonly used as the core of fiber optic cables?
A. Copper
B. Aluminum
C. Glass or plastic
D. Steel
Answer: C. Glass or plastic
Rationale: The core is made of highly transparent glass or plastic to
allow light transmission.
,3. What does cladding do in a fiber optic cable?
A. Protects outer jacket only
B. Reflects light back into the core
C. Conducts electricity
D. Amplifies signals
Answer: B. Reflects light back into the core
Rationale: Cladding keeps light signals inside the core through total
internal reflection.
4. What phenomenon allows fiber optics to transmit light efficiently?
A. Refraction loss
B. Electrical conduction
C. Total internal reflection
D. Magnetic induction
Answer: C. Total internal reflection
Rationale: Light is reflected within the core due to differences in
refractive index.
5. Which tool is used to measure optical power?
A. Multimeter
B. OTDR
C. Optical power meter
D. Voltmeter
Answer: C. Optical power meter
Rationale: It measures the strength of light signals in fiber optic
systems.
,6. What does OTDR stand for?
A. Optical Transmission Data Router
B. Optical Time Domain Reflectometer
C. Optical Testing Data Receiver
D. Output Transmission Digital Reader
Answer: B. Optical Time Domain Reflectometer
Rationale: OTDR is used to test fiber length, faults, and splices.
7. Which type of fiber is best for long-distance communication?
A. Plastic fiber
B. Multimode fiber
C. Single-mode fiber
D. Coaxial fiber
Answer: C. Single-mode fiber
Rationale: Single-mode fiber reduces signal loss over long distances.
8. What is the typical core size of single-mode fiber?
A. 50 microns
B. 62.5 microns
C. 9 microns
D. 125 microns
Answer: C. 9 microns
Rationale: Single-mode fibers have a very small core for one light path.
, 9. Which connector is commonly used in fiber optics?
A. RJ45
B. SC connector
C. USB connector
D. HDMI connector
Answer: B. SC connector
Rationale: SC connectors are widely used for fiber optic termination.
10. What is fiber attenuation?
A. Signal amplification
B. Signal loss over distance
C. Signal conversion
D. Signal reflection
Answer: B. Signal loss over distance
Rationale: Attenuation refers to weakening of light signal as it travels.
11. What causes macro-bending loss?
A. Electrical interference
B. Large physical bends in fiber
C. High voltage
D. Temperature increase
Answer: B. Large physical bends in fiber
Rationale: Sharp bends cause light to escape the core.
12. Which light source is commonly used in fiber optics?
