Practice Exam 1

Question 1

Light is electromagnetic energy with a ______ frequency and a ________ wave length

Answer 1

Higher

Lower

Question 2

Fiber optic transmission takes place in the ______ portion of the light spectrum

Answer 2

Infared

Question 3

A simple fiber optic system would consist of what four parts

Answer 3

Transmitter( LED, Laser, VCSEL) fiber optic cable, receiver (PIN, APD), connectors

Question 4

What absolute power value is zero dBm reference to

Answer 4

1mw

Question 5

Absolute power in optical fiber is specified ass

Answer 5

dBm is power

dB is loss

Question 6

Attenuation in optical fiber is lowest at what wave length

Answer 6

1550nm

Question 7

What are the three most common wavelength windows used for communications through optical fibers

Answer 7

850, 1300, 1550

Question 8

In North America what year was the first fiber optic telephone system installed

Answer 8

1977

Question 9

Single mode fiber optic systems typically use what light source

Answer 9

Laser ( Light Amplification by Stimulated Emissions of Radiation)

Question 10

Multi mode fiber optic transmitters typically use what two low cost light sources

Answer 10

LED

VCSEL

Question 11

Different wavelengths of light travel at ______ speeds through the glass

Answer 11

Different

Question 12

Single mode fiber’s have a ________ core compared to multimode fibers

Answer 12

8.3-10um

Question 13

The typical numerical aperture(NA) for a 50/125um optical fiber is

Answer 13

.200

Question 14

One way to reduce modal dispersion is to

Answer 14

Shrink the core size

Question 15

The number of modes in an optical fiber increases as the _______ decreases

Answer 15

Wavelength

Question 16

What optical effect is produced by all mechanical interconnections, whether mechanical splices or mated connector pairs

Answer 16

Fresnal Reflection

Question 17

When light passes from one transparent medium to another transparent medium that has a different refractive index, the light wave bands. This is called

Answer 17

Refraction

Question 18

Which parts of the multimode optical fiber cable has the lowest refractive index

Answer 18

Cladding

Question 19

Single mode systems usually operate at what three wavelengths

Answer 19

1310, 1550, 1625

Question 20

What are the two most common multimode wavelengths

Answer 20

850nm

1300nm

Question 21

Attenuation( loss ) is specified as

Answer 21

Loss Measured in dB

Question 22

What is a “mode” in optical fiber

Answer 22

Light Path

Question 23

Improper bending of an optical fiber will do what to the tensile strength

Answer 23

Weaken

Question 24

OM3 and OM4 multi mode fiber’s are commonly known as ________ fibers

Answer 24

Laser Optimized

Question 25

What are the two most common multimode optical fiber types

Answer 25

50/125um Europe

62.5/125um USA