FOT (Fiber Optics Technician) Exam
- Which phenomenon allows light to propagate through the fiber core?
- Diffraction
- Total internal reflection
- Dispersion
- Refraction
Answer: B
Explanation: Fiber optics rely on total internal reflection to keep light within the core.
- What is the primary function of the cladding in a fiber optic cable?
- To absorb unwanted light
- To protect the outer jacket
- To keep light confined in the core
- To increase signal attenuation
Answer: C
Explanation: The cladding has a lower refractive index than the core, ensuring
total internal reflection. 1 / 4
FOT (Fiber Optics Technician) Exam
- Which type of fiber is typically used for long-distance telecommunication?
- Plastic fiber
- Multimode fiber
- Step-index fiber
- Single-mode fiber
Answer: D
Explanation: Single-mode fiber has a smaller core diameter, reducing dispersion
and enabling longer transmission distances.
- Which wavelength range is most commonly used for long-haul fiber optic
- 850 nm
- 980 nm
- 1310 nm and 1550 nm
- 650 nm
communication?
Answer: C
Explanation: 1310 nm and 1550 nm bands are standard for long-distance
communication due to low attenuation and dispersion. 2 / 4
FOT (Fiber Optics Technician) Exam
- Which of the following correctly describes dispersion in fiber optics?
- Light signal broadening over distance
- Sudden loss of light due to bending
- The absorption of light in the cladding
- Reflection of light at the fiber end
Answer: A
Explanation: Dispersion causes pulse spreading, which can limit bandwidth and
transmission distance.
- Which component converts electrical signals into optical signals?
- Photodiode
- Optical transmitter
- Optical coupler
- Optical amplifier
Answer: B
Explanation: The optical transmitter (often a laser diode or LED) is responsible for converting electrical signals to optical signals. 3 / 4
FOT (Fiber Optics Technician) Exam
- In fiber optics, what does NA (Numerical Aperture) represent?
- The ratio of cladding to core diameter
- The ability of a fiber to gather light
- The fiber’s bending radius limit
- The level of polarization in a fiber
Answer: B
Explanation: NA measures the light-gathering or light-acceptance capability of a fiber.
- Why is single-mode fiber preferred for higher bandwidths over long distances?
- It has a larger core diameter
- It has multiple modes that combine signals
- It has minimal modal dispersion
- It requires no connectors
Answer: C
Explanation: Single-mode fiber limits modal dispersion because light travels in
essentially one mode, allowing higher bandwidth over long distances.
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