Deck 13: Physical Layer Data Transmissions

Question 1

The following figure shows the process of __________ in data transmissions?

A) frequency division multiplexing
B) amplitude modulation
C) frequency modulation
D) statistical time division multiplexing
E) time division multiplexing

Answer 1

NA

Question 2

The intermediary device in the figure must be a:

A) coder
B) CSU/DSU
C) multiplexer
D) decoder
E) modem

Answer 2

E

Question 3

Which device makes conversion from one digital signal format to another digital signal format?

A) Dial up modem
B) CSU/DSU
C) Multiplexer
D) DSL modem
E) Cable modem

Answer 3

B

Question 4

Imagine this mode of transmissions that combine data from three different sources. The signaling uses ____ technologies:

A) baseband and frequency division multiplexing
B) broadband and time division multiplexing
C) broadband and phase division multiplexing
D) baseband and time division multiplexing
E) broadband and frequency division multiplexing

Question 5

Imagine this mode of transmissions that combine data from three different sources. The signaling uses ____ technologies:

A) baseband and frequency division multiplexing
B) broadband and time division multiplexing
C) broadband and phase division multiplexing
D) baseband and time division multiplexing
E) broadband and frequency division multiplexing

Question 6

Which is CORRECT?

A) The Optical Carrier (OC) is an ITU-T international standard.
B) DS (Digital Signal) speeds are multiples of 64Kbps, data rate of a voice call.
C) Optical Carrier (OC) speeds are multiples of 155 Mbps.
D) The STM (Synchronous Transport Module) standard was introduced for twisted pairs.
E) Both DS and OC standards were introduced at the same time.

Question 7

Which connection would need cross-over cabling?

A) Switch - router
B) PC - switch
C) Server - switch
D) Wireless access point - router
E) Switch - switch

Question 8

Compared with optical fibers, twisted pairs:

A) Have a larger bandwidth
B) Better protect data in transit
C) Have higher interference
D) Have lower attenuation
E) Have a higher segment length

Question 9

UTP categories such as Category 6 should rate the _____.

A) overall quality
B) number of wires included
C) price per foot
D) transmission error rate
E) degree of resistance to external noise

Question 10

Choose a CORRECT statement on the optical fiber.

A) The multi-mode fiber has lower attenuation than the single-mode fiber.
B) The single mode fiber should have a larger core than the multi-mode fiber.
C) The multi-mode fiber has a longer transmission distance than the single-mode fiber.
D) Transmitting multiple light signals concurrently in a single-mode fiber is not possible with current technology.
E) The single-mode fiber is a preferred choice in laying WAN backbone links.

Question 11

The data transmission method shown in the figure is using _______

A) multiplexing
B) modulation
C) narrowband
D) synchronous transmission
E) asynchronous transmission

Question 12

When the optical fiber is compared to the copper wire, the copper wire _____.

A) has a larger bandwidth
B) is more resistant to signal interface
C) is generally more costly in installation
D) has higher attenuation during signal propagation.
E) offers better signal security.

Question 13

Which statement is NOT true about optical fibers?

A) Optical fibers are designed to transmit light signals instead of electronic signals.
B) Multi-mode fibers have a larger diameter than single-mode fibers.
C) Single-mode fibers are more reliable than multi-mode fibers for long distance transmission.
D) Several signals can be transmitted concurrently on a single fiber by using multiplexing.
E) Multi-mode fibers have a larger transmission capacity than single-mode fibers.

Question 14

Choose a TRUE statement regarding the twisted pair.

A) The details of the twisted pair cable are data link layer standards.
B) The twisted pair cable contains a 2 pair bundle, one for sending and another for receiving.
C) The maximum segment lenght of UTP between two network nodes is generally 100 meters.
D) The twisted pair cable uses on/off signaling to transmit messages.
E) Most twisted pairs in use today are STP.

Question 15

Signals attenuate most quickly when they travel through the ________.

A) single-mode fiber
B) multi-mode fiber
C) air (or atmosphere)
D) unshielded twist pair
E) coaxial cable

Question 16

What could be a major reason that multi-mode fibers are used instead of single-mode fibers for LANs?

A) higher speed
B) lower cost
C) longer propagation distance
D) lower error rate
E) lower dispersion

Question 17

This figure demonstrates how the Asymmetric DSL (or ADSL) broadband technology is providing voice and data transmissions concurrently through __________.

A) time division multiplexing
B) frequency division multiplexing
C) amplitude modulation
D) frequency modulation
E) statistical time division multiplexing

Question 18

Below figure represents the mechanism used by the T-1 service to transmit data using _________ technology at the physical layer.

A) Modulation
B) Multiplexing
C) Asynchronous transmission
D) Broadband
E) Spread spectrum

Question 19

Below figure includes examples of _________ technology.

A) Digital signal encoding
B) Multiplexing
C) Asynchronous transmission
D) Spread spectrum
E) Broadband