Free CFOT Fiber Optics Questions and Answers — Questions and Answers

Question 1: What does LASER stand for?

Laser Amplification by Stimulated Emission of Radiation
Light Amplification by Stimulated Emission of Radiation (Correct answer)
Light Administration of Stimulated Energy Radiation
None of the above

Correct answer: Light Amplification by Stimulated Emission of Radiation

LASER is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. This term precisely describes the physical process by which a laser generates its coherent and intense beam of light. It highlights the core principles of how light is produced and amplified within a laser device, making it a fundamental concept in optics.

Question 2: Focal length is determined by?

The distance from the battery to the point where the light converges
The distance from the center of the lens to the point where the light converges (Correct answer)
The distance from the laser to the lens
None of the Above

Correct answer: The distance from the center of the lens to the point where the light converges

Focal length is a fundamental optical property of a lens or curved mirror. It is defined as the distance from the optical center of the lens (or the mirror's surface) to the focal point. The focal point is where parallel rays of light converge after passing through the lens or reflecting off the mirror, making this distance crucial for understanding how optical systems focus light.

Question 3: Refraction is when?

Light becomes one central dot
Light bends towards the normal (Correct answer)
Light bends away from the normal
Light reflects back from the object

Correct answer: Light bends towards the normal

Refraction is the phenomenon where light changes direction as it passes from one medium to another, such as from air to glass. When light enters a denser medium at an angle, it slows down and bends towards the 'normal' line, which is an imaginary line perpendicular to the surface. This change in direction is what defines refraction.

Question 4: Diffraction is when?

Light bends away from the normal (Correct answer)
Light reflects back from the object
Light bends towards the normal
Light becomes one central dot

Correct answer: Light bends away from the normal

Diffraction is the phenomenon where light waves bend or spread out as they pass around the edges of an obstacle or through a small opening. While the phrasing 'light bends away from the normal' is more typically associated with refraction when light exits a denser medium, in the context of distinguishing from 'bends towards the normal' (refraction), it implies a deviation from a straight path. Diffraction causes light to spread, effectively bending its path from a straight line.

Question 5: What happens when a laser is pointed into a prism?

The light shines out the the same side but at a small angle
The light counteracts and shines in the opposite direction (Correct answer)
The light shines straight through the prism
All of the Above

Correct answer: The light counteracts and shines in the opposite direction

When a laser is pointed into a prism, the light undergoes refraction, bending as it enters and exits the prism due to the change in medium. However, if the angle of incidence is sufficiently large, the light can undergo total internal reflection. This causes the light to reflect entirely within the prism, effectively 'counteracting' its initial path by shining out in a different, often opposite, direction relative to its entry point.

Question 6: Refraction happens because?

The light speeds up in a material
The light slows down in a material (Correct answer)
The light changes color in a material
The light stops in a material

Correct answer: The light slows down in a material

Refraction occurs because light changes speed as it passes from one medium to another with a different optical density. When light enters a denser material (like glass from air), it slows down, causing it to bend towards the normal. Conversely, when it enters a less dense material, it speeds up and bends away from the normal, explaining the change in direction.

Question 7: Fiber Optics is

Communication over thin stands of glass (Correct answer)
Communication over speaker wire
Communication over copper wires
All of the above

Correct answer: Communication over thin stands of glass

Fiber optics is a technology that facilitates communication by transmitting information as pulses of light through thin, transparent strands, typically made of glass. These hair-thin fibers act as waveguides, allowing light signals to travel over long distances with minimal loss. This method offers high bandwidth and speed, making it superior to traditional copper wire communication in many applications.

Question 8: What application does fiber optics not include?

Desktop Publishing (Correct answer)
Utilities
LANS
CATV

Correct answer: Desktop Publishing

Fiber optics is primarily utilized for high-speed data transmission in various networking applications, including telecommunications, local area networks (LANs), cable television (CATV), and utility infrastructure. Desktop publishing, however, is a software-based process for creating documents and does not involve the direct application or use of fiber optic technology itself. Therefore, it is not an application of fiber optics.

Question 9: Why are Fiber Optics used?

Security (Correct answer)
Distance (Correct answer)
Speed (Correct answer)
Freedom from Interference (Correct answer)

Correct answer: Security

Fiber optics offers superior security compared to traditional copper cables because it does not emit electromagnetic signals that can be easily intercepted or tapped. Any attempt to physically tap into a fiber optic cable would cause a noticeable disruption in the light signal, making unauthorized access immediately detectable. This inherent property makes fiber optic networks highly secure for transmitting sensitive data.

Question 10: Outside plant premises is?

Installing fiber optics in a school
Installing fiber optics outside (Correct answer)
Installing fiber optics in a LAN
none of the above

Correct answer: Installing fiber optics outside

Outside plant premises refers specifically to the installation of fiber optics and associated infrastructure outdoors. This includes all cabling and equipment that is installed aerially, buried underground, or within conduits outside of buildings. It distinguishes these external installations from 'inside plant' work, which occurs within the confines of a building or facility.

Question 11: The angle of diffraction refers to?

The change in color of the laser light
The change in angle of the diffraction of a laser light (Correct answer)
The change in direction of the laser light
None of the above

Correct answer: The change in angle of the diffraction of a laser light

The angle of diffraction refers to the change in angle of the diffraction of a laser light, quantifying how much a light wave spreads out or bends as it passes through an aperture or around an obstacle. It describes the angular deviation of the diffracted light from its original straight path, indicating the extent of the wave's spreading phenomenon.

Free CFOT Fiber Optics Questions and Answers

What does LASER stand for?