Transmission Media Are Usually Categorized As s3a6l

Transmission media are usually categorized as _______. A)

fixed or unfixed

B) C)

guided or unguided determinate or indeterminate

D)

2

CORRECT

metallic or nonmetallic

Transmission media lie below the _______ layer. A)

physical

B)

network

C)

transport

D)

3

INCORRECT

application

_______ cable consists of an inner copper core and a second conducting outer sheath. A)

Twisted-pair B)

Coaxial

C) D)

4

INCORRECT

Fiber-optic

Shielded twisted-pair

In fiber optics, the signal is _______ waves. A)

light

B) C)

radio infrared

D)

5

INCORRECT

very low-frequency

Which of the following primarily uses guided media? A)

cellular telephone system

B)

local telephone system

C)

satellite communications

D)

6

INCORRECT

radio broadcasting

Which of the following is not a guided medium? A)

twisted-pair cable

B) C) D)

7

INCORRECT

coaxial cable fiber-optic cable atmosphere

What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable? A)

inner conductor

B)

diameter of cable

C)

outer conductor

D)

insulating material

8

INCORRECT

In an optical fiber, the inner core is _______ the cladding. A)

denser than

B) C)

less dense than the same density as

D)

9

INCORRECT

another name for

The inner core of an optical fiber is _______ in composition. A)

glass or plastic B) C)

copper bimetallic

D)

1 0

INCORRECT

When a beam of light travels through media of two different densities, if the angle of incidence is greater than the critical angle, _______ occurs.

A)

reflection

B)

refraction

C)

incidence

D)

1 1

INCORRECT

liquid

criticism

When the angle of incidence is _______ the critical angle, the light beam bends along the interface.

A)

more than

B)

less than

C) D)

1 2

equal to

none of the above

Signals with a frequency below 2 MHz use _______ propagation. INCORRECT

A)

ground B)

C) D)

1 3

sky

line-of-sight none of the above

Signals with a frequency between 2 MHz and 30 MHz use ______ propagation. INCORRECT

A)

ground B)

C) D)

1 4

sky

line-of-sight none of the above

Signals with a frequency above 30 MHz use _______propagation. INCORRECT

A)

ground B)

C)

line-of-sight

sky

D)

1 5

none of the above

A parabolic dish antenna is a(n) _______ antenna. CORRECT

A)

omnidirectional

B)

bidirectional

C)

unidirectional D)

1 6

A(n) _____ medium provides a physical conduit from one device to another. CORRECT

A) B) C)

guided unguided

either (a) or (b)

D)

1 7

horn

none of the above

________ cable consists of two insulated copper wires twisted together. CORRECT

A) B) C) D)

Coaxial Fiber-optic Twisted-pair

none of the above

1 8

_______ cable is used for voice and data communications. INCORRECT

A) B)

Fiber-optic

C)

Twisted-pair

D)

1 9

none of the above

__________ consists of a central conductor and a shield. CORRECT

A) B) C) D)

2 0

Coaxial

Coaxial Fiber-optic Twisted-pair

none of the above

_____ cable can carry signals of higher frequency ranges than _____ cable. INCORRECT

A)

Twisted-pair; fiber-optic

B)

Coaxial; fiber-optic

C)

Coaxial; twisted-pair

D)

none of the above

2 1

INCORRECT

______ cables are composed of a glass or plastic inner core surrounded by cladding, all encased in an outside jacket.

A) B)

Fiber-optic

C)

Twisted-pair

D)

2 2

none of the above

______ cables carry data signals in the form of light. INCORRECT

A) B) C) D)

2 3

INCORRECT

Fiber-optic Twisted-pair

In a fiber-optic cable, the signal is propagated along the inner core by _______.

D)

INCORRECT

Coaxial

none of the above

A)

reflection

B)

refraction

C)

2

Coaxial

modulation none of the above

_________ media transport electromagnetic waves without the use of a physical conductor.

4 A)

Guided

B) C) D)

2 5

Unguided Either (a) or (b) None of the above

Radio waves are _________. INCORRECT

A)

omnidirectional

B)

unidirectional

C) D)

2 6

none of the above

Microwaves are _________. INCORRECT

A) B) C) D)

2 7

bidirectional

INCORRECT

omnidirectional unidirectional bidirectional none of the above

_______ are used for cellular phone, satellite, and wireless LAN communications.

A)

Radio waves

B) C) D)

2 8

INCORRECT

Microwaves Infrared waves none of the above

________ are used for short-range communications such as those between a PC and a peripheral device.

A) B) C) D)

Radio waves Microwaves Infrared waves none of the above