Final Examination_ECE 13_Intersem

1. 1.     What is the lifetime of ILDs?

• 50,000 hours

• 75,000 hours

• 100,000 hours

• 125,000 hours

2. 2.     Proposed the used of clad glass fiber as a dielectric waveguide

• Karpon and Keck

• Karpon and Bockham

• Bockham and Kao

• Kao and Keck

3. 3. What is known as the different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted?

• Acceptance angle

• Mode

• Sensor

• Aperture

4. 4. Infrared range for fiber optics.

• 400-700nm

• 700-1200nm

• 300-2000nm

• 400-7000nm

5. 5. Most fiber-optic light sources emit light in which spectrum?

• Visible

• Infrared

• Ultraviolet

• X-ray

6. Repeaters are placed approximately every ____ in marine fiber optic cables to regenerate optical signals and compensate for signal loss.

• 50km

• 100km

• 28km

• 80km

7. 7. The core of an optical fiber has a

• Lower refracted index than air

• Lower refractive index than the cladding

• Higher refractive index than the cladding

• Similar refractive index with the cladding

8.  What type of fiber has the highest

modal dispersion?

• Step-index single mode

• Graded index mode

• Step-index multimode

• Graded index multimode

9. 9. The main benefit of light-wave communications over microwaves or any other communications media is

• lowest

• better security

• wider bandwidth

• freedom from interface

10. 10. What does the acceptance half-angle determine in fiber optics?

• The maximum distance between two fiber optic cables

• The minimum wavelength of light that can be transmitted through a fiber

• The maximum angle at which light can enter a fiber and still be transmitted effectively

• The speed of light propagation within the fiber