Deck 3: Physical Layer

Question 1

In simplex transmission, the data flows in both directions at the same time

Answer 1

False

Question 2

Fiber optic cable carries signals in traditional electrical form.

Answer 2

False

Question 3

Digital transmission produces more errors than analog transmission.

Answer 3

False

Question 4

Coaxial cable costs less and offers less shielding to electrical interference than twisted pair cable.

Question 5

A walkie-talkie is an example of half-duplex transmission.

Question 6

A physical circuit refers to the transmission characteristics of the connection, such as the speed at which data is being sent through the connection.

Question 7

With modem communications, the receiving modem converts the incoming digital signal from the telephone line into an analog signal that can be understood by the computer.

Question 8

The amount of time it takes to switch between sending and receiving in half-duplex transmission is called the propagation delay.

Question 9

Multimode fiber is capable of longer transmission distances than single mode fiber.

Question 10

In full-duplex transmission, two stations can send and receive simultaneously.

Question 11

Propagation delay is negligible with satellite transmission.

Question 12

Microwave transmissions require a line of sight between any two points.

Question 13

Guided media refers to the type of media in which the message is broadcast through the air.

Question 14

The medium is the physical matter or substance that carries the voice or data transmission.

Question 15

Radio data transmission requires that each device has a radio receiver/transmitter and uses a specific frequency.

Question 16

In a multipoint circuit configuration, each computer has a dedicated circuit between itself and each of the other computers in the network.

Question 17

Newer telephone circuits, built during the last decade, offer higher quality because they were built using analog transmission.

Question 18

WDM is a version of FDM used in fiber-optic cables.

Question 19

In a multipoint circuit configuration, each computer can use the circuit at the same time.

Question 20

Computers produce digital data whose values are binary: 0 or 1.

Question 21

With nonreturn to zero signaling, the voltage alternates between zero and a positive or negative voltage.

Question 22

Digital transmission occurs when the signal sent over the transmission media constantly varies among an infinite number of states.

Question 23

Serial mode transmission is much faster than parallel mode transmission.

Question 24

Signal bandwidth is the difference between the highest and lowest frequencies in a band.

Question 25

Frequency is the number of cycles per second and is expressed in Hertz.

Question 26

Manchester encoding is a special type of bipolar signaling in which the signal is changed from high to low or from low to high in the middle of the signal.

Question 27

Radio, microwave and satellite are all examples of guided media.

Question 28

ASCII is the least popular code for data communications.

Question 29

Ethernet, a common LAN technology, uses Manchester encoding.

Question 30

Nonreturn to zero is a type of unipolar signaling

Question 31

Amplitude, frequency and phase are all characteristics of a sound wave.

Question 32

One form of interference with satellite transmission is called raindrop attenuation in which the transmissions are absorbed by heavy rain.

Question 33

Coding schemes are groups of bits that translate into the "alphabet" of any given system.

Question 34

The predominant method of transferring information internally in a computer is via parallel mode.

Question 35

Of all the media available, fiber optic provides the highest transmission speeds.

Question 36

Frequency modulation refers to the changing of the height of the sound wave.

Question 37

Data compression can increase the throughput of a communication link.

Question 38

A codec converts an incoming digital signal to an analog signal for transmission over an analog network.

Question 39

Baud rate is the number of bits transmitted per second.

Question 40

Fiber optic cable can only be used on LANs.

Question 41

Multiplexing increases the cost of provisioning network circuits.

Question 42

Based on the TIA/EIA 568-B structured cabling standard, the cabling that runs from the telecommunications closet to each work area is called backbone cabling.

Question 43

Multitasking means to break one high-speed physical communication circuit into several lower-speed logical circuits so that different devices can simultaneously use it.

Question 44

Two fundamentally different types of data are:

A)DSL and ADSL
B)asymmetric and symmetric
C)Microsoft and IBM
D)digital and analog
E)local area and wide area

Question 45

Statistical time division multiplexing does not require the capacity of the circuit to be equal to the sum of the combined circuits.

Question 46

Which is not true about point-to-point circuits?

A)point-to-point circuits are dedicated to the use of the two computers.
B)point-to-point circuits are more expensive than multipoint circuits.
C)point-to-point circuits are called dedicated circuits.
D)point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits.
E)point-to-point circuits are used when the computers generate enough traffic to fill the capacity of the communication circuit.

Question 47

The "local loop" refers to the wires that run from the customer premises to the telephone switch of the telephone company.

Question 48

Frequency division multiplexing divides the circuit into a set of different time slots.

Question 49

One way to reduce quantizing errors is to increase the sampling rate of the analog signal.

Question 50

Digital transmission permits higher maximum transmission rates when compared to analog.

Question 51

Data is physically transmitted from one computer or terminal to another in the ________ layer.

A)physical
B)transport
C)application
D)terminal
E)data link

Question 52

Time division multiplexing is more efficient that frequency division multiplexing because the guardbands used in the frequency division multiplexing or not needed.

Question 53

____________ refers to the transmission characteristics of the circuit.

A)handshaking
B)virtual circuit
C)bonding
D)logical circuit
E)physical circuit

Question 54

In general, older networks and local loops designed to transmit voice data are likely to be ________.

A)international
B)level 2
C)numeric
D)digital
E)analog

Question 55

An) __________ circuit is another name for a multipoint configuration.

A)analog
B)dedicated
C)point-to-point
D)shared
E)simplex

Question 56

In general, networks designed to transmit primarily computer data are likely to be ________.

A)international
B)level 1
C)numeric
D)analog
E)digital

Question 57

Wavelength division multiplexing can only used with copper cables.

Question 58

Which of the following is not a key advantage of digital transmission?

A)It permits only low transmission rates.
B)It is more efficient.
C)It is simpler to integrate voice, video, and data on the same circuit.
D)It is more secure.
E)It produces fewer errors.

Question 59

_________ is the basic physical layout of the circuit.

A)point-to-point configuration
B)configuration
C)circuit configuration
D)circuit design
E)circuit plan

Question 60

Having a conversation with someone using a cellular phone is an example of _________ transmission.

A)simplex
B)full-duplex
C)half-duplex
D)analog
E)digital

Question 61

The earliest type of fiber optic systems were:

A)Graded index multimode
B)Attenuated
C)Multimode
D)Single mode
E)Step mode

Question 62

Which of the following is not an important factor to consider when selecting media to be used in a network?

A)prestige value of the type of media
B)type of network
C)cost
D)transmission distance
E)security

Question 63

______________ refers to the time it takes for a signal to travel from sender to recipient highly exaggerated with satellite transmission).

A)Line-of-sight effect
B)Multimode index
C)Saturation effect
D)Raindrop attenuation
E)Propagation delay

Question 64

_____________ can be thought of as dividing the circuit horizontally.

A)Frequency division multiplexing
B)Statistical frequency division multiplexing
C)Statistical time division multiplexing
D)Time division multiplexing
E)Wavelength division multiplexing

Question 65

The two basic types of media are:

A)statistical and frequency
B)guided and wireless radiated)
C)local and wide area
D)attenuator and Gaussian
E)duplexed and non-duplexed

Question 66

Another term for the weakening of a signal over distance is:

A)turnaround time
B)propagation delay
C)dispersion
D)insulation
E)attenuation

Question 67

___________ refers to the spreading of the signal that different parts of the signal arrive at different times at the destination.

A)turnaround time
B)propagation delay
C)dispersion
D)insulation
E)attenuation

Question 68

Which of the following would be considered a type of wireless media?

A)unshielded twisted pair
B)shielded twisted pair
C)coaxial cable
D)microwave
E)fiber optics

Question 69

Which of the following media has the lowest error rates and the highest transmission speeds?

A)Coaxial cable
B)unshielded twisted pair
C)shielded twisted pair
D)fiber optic cable
E)infrared

Question 70

____________ is one of the most commonly used coding schemes used in data transmission.

A)ASCII
B)ISDN
C)MAU
D)ATM
E)FDM

Question 71

__________ is a line-of-sight type of wireless media.

A)coaxial cable
B)microwave
C)radio
D)twisted pair
E)fiber optic

Question 72

The type of media usually installed on homes and businesses by the telephone company is called ____________.

A)fiber optic cable
B)coaxial cable
C)twisted pair
D)phone cable
E)phone wire

Question 73

Microwave transmission:

A)is a type of high frequency radio communication
B)requires a clear line-of-sight path
C)is typically used for long distance data transmission
D)does not require the laying of any cable
E)all of the above

Question 74

The representation of the character A by the group of 8 bits, 01000001, is an example of:

A)digital coding
B)phase modulation
C)binary modulation
D)analog transmission
E)pitch variation

Question 75

Transmission speeds:

A)are the same among all media
B)are not a factor in selecting a media because all media have more than enough speed to serve current communication demands
C)are a constant, 56Kbps, for all media types
D)differ widely among media
E)always have a direct correlation with security

Question 76

The ability to transmit in both directions, but only in one direction at a time is an example of _______________ transmission.

A)simplex
B)full-duplex
C)half-duplex
D)analog
E)digital

Question 77

A coding scheme that uses 10 bits to represent each character is capable of representing _________ different characters.

A)256
B)20
C)200
D)512
E)1024

Question 78

When all bits of a character are transferred one after another, the bits are transferred in ___________ mode.

A)serial
B)frequency division
C)multiplexing
D)parallel
E)full complex

Question 79

Which of the following media can best withstand harsh environmental conditions?

A)shielded twisted pair
B)unshielded twisted pair
C)Cat 5 twisted pair
D)coaxial cable
E)fiber optic cable

Question 80

Which of the following is the most secure wired media?

A)coaxial cable
B)unshielded twisted pair
C)shielded twisted pair
D)fiber optic cable
E)infrared