Deck 3: Physical Layer

Question 1

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

Answer 1

False

Question 2

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

Answer 2

True

Question 3

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

Answer 3

False

Question 4

Digital transmission produces more errors than analog transmission.

Question 5

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

Question 6

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

Question 7

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

Question 8

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

Question 9

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

Question 10

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

Question 11

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

Question 12

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

Question 13

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

Question 14

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 15

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

Question 16

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

Question 17

Propagation delay is negligible with satellite transmission.

Question 18

Fiber optic cable carries signals in traditional electrical form.

Question 19

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

Question 20

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

Question 21

Nonreturn to zero is a type of unipolar signaling

Question 22

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

Question 23

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

Question 24

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

Question 25

Fiber optic cable can only be used on LANs.

Question 26

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

Question 27

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

Question 28

Data compression can increase the throughput of a communication link.

Question 29

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

Question 30

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

Question 31

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

Question 32

Baud rate is the number of bits transmitted per second.

Question 33

Serial mode transmission is much faster than parallel mode transmission.

Question 34

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

Question 35

Ethernet, a common LAN technology, uses Manchester encoding.

Question 36

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 37

ASCII is the least popular code for data communications.

Question 38

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

Question 39

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

Question 40

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

Question 41

Wavelength division multiplexing can only used with copper cables.

Question 42

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 43

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

Question 44

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

Question 45

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 46

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

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

Question 47

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

Question 48

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

Question 49

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 50

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

Question 51

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 52

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 53

____________ refers to the transmission characteristics of the circuit.

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

Question 54

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

Question 55

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 56

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 57

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 58

_________ 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 59

Multiplexing increases the cost of provisioning network circuits.

Question 60

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 61

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 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

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 64

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 65

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 66

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 67

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

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

Question 68

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

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

Question 69

___________ 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 70

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 71

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

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

Question 72

The earliest type of fiber optic systems were:

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

Question 73

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 74

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 75

______________ 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 76

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 77

_____________ 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 78

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 79

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

Question 80

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