WGU D413 TELECOMMUNICATIONS
AND WIRELESS COMMUNICATIONS
COMPLETE 200 QUESTION MASTER
PRACTICE EXAM
1. Which layer of the OSI model is responsible for logical addressing,
such as IP addresses, and determining the best path for data to
travel?
A. Data Link Layer
B. Network Layer
C. Transport Layer
D. Physical Layer
Rationale: The Network Layer (Layer 3) handles routing and IP
addressing to ensure data reaches the correct destination across
different networks.
2. A network engineer needs a cable that is completely immune to
Electromagnetic Interference (EMI) for a run near high-voltage
machinery. Which should they choose?
A. Cat6a Unshielded Twisted Pair (UTP)
B. RG-6 Coaxial Cable
C. Fiber-optic Cable
D. Cat7 Shielded Twisted Pair (STP)
Rationale: Fiber-optic cables use light pulses rather than
electrical signals, making them entirely immune to EMI and radio
frequency interference.
3. Which technology allows multiple data streams to be sent over a
single high-capacity fiber-optic cable by using different
wavelengths of laser light?
A. Time Division Multiplexing (TDM)
B. Frequency Division Multiplexing (FDM)
C. Dense Wavelength Division Multiplexing (DWDM)
D. Statistical Multiplexing
Rationale: DWDM is a fiber-optic technology that maximizes
bandwidth by multiplexing many signals onto a single fiber using
various wavelengths (colors) of light.
,4. Which 802.11 wireless standard was the first to introduce MIMO
(Multiple-Input Multiple-Output) technology to increase
throughput?
A. 802.11b
B. 802.11g
C. 802.11n
D. 802.11a
Rationale: 802.11n introduced MIMO, using multiple antennas to
send and receive more data simultaneously, significantly
increasing speed and range.
5. An administrator needs to automatically assign IP addresses to
200 new workstations. Which protocol is designed for this task?
A. DNS
B. DHCP
C. SNMP
D. ARP
Rationale: The Dynamic Host Configuration Protocol (DHCP)
automates the process of assigning IP addresses, subnet masks,
and default gateways to devices on a network.
6. Which device operates primarily at the Data Link Layer (Layer 2)
and uses MAC addresses to forward data only to the specific port
where the destination device is connected?
A. Hub
B. Router
C. Switch
D. Repeater
Rationale: Unlike a hub, which broadcasts to everyone, a switch
learns MAC addresses and directs traffic specifically to the
intended recipient.
7. In telecommunications, what is the primary purpose of a
CSU/DSU (Channel Service Unit/Data Service Unit)?
A. To route traffic between different VLANs.
B. To act as a digital interface between a LAN and a high-
speed digital carrier line (like a T1).
C. To convert analog voice to digital VoIP packets.
D. To provide wireless encryption for mobile devices.
Rationale: The CSU/DSU acts as a digital "modem" that converts
data from a router into a format understood by digital leased
lines.
,8. Which modulation technique changes both the amplitude and the
phase of the carrier wave to represent data bits, allowing for higher
data rates?
A. Frequency Shift Keying (FSK)
B. Amplitude Shift Keying (ASK)
C. Quadrature Amplitude Modulation (QAM)
D. Binary Phase Shift Keying (BPSK)
Rationale: QAM is highly efficient because it manipulates two
characteristics of the wave simultaneously, allowing more bits to
be packed into each symbol.
9. A business wants to connect several buildings in a city. Which type
of network is specifically designed for a geographic area the size of
a city or large campus?
A. LAN
B. PAN
C. MAN
D. WAN
Rationale: A Metropolitan Area Network (MAN) spans a city or
large campus, sitting between a local LAN and a global WAN.
10. Which wireless security protocol provides the strongest
encryption and protection against "KRACK" attacks by using a 4-
way handshake?
A. WEP
B. WPA
C. WPA2
D. WPA3
Rationale: WPA3 is the most modern security standard, offering
individualized data encryption and better protection against
brute-force attacks.
11. Which type of signal impairment occurs when a signal loses
strength as it travels further away from the source?
A. Crosstalk
B. Attenuation
C. Dispersion
D. Jitter
Rationale: Attenuation is the natural weakening of a signal over
distance; it is the reason why cables have maximum length limits.
, 12.What is the standard impedance for an RG-6 coaxial cable
commonly used in cable television and satellite installations?
A. 50 ohms
B. 75 ohms
C. 100 ohms
D. 120 ohms
Rationale: RG-6 is designed for video and high-speed internet
applications, which require a 75-ohm impedance to minimize
signal reflection.
13.Which IoT wireless protocol is characterized by low power
consumption and is commonly used in mesh networks for home
automation?
A. Wi-Fi (802.11ac)
B. Zigbee
C. WiMAX
D. LTE
Rationale: Zigbee (802.15.4) is a low-power, short-range wireless
standard ideal for creating mesh networks of smart home devices.
14.A technician is troubleshooting a VoIP call that has inconsistent
delays between packets, causing "choppy" audio. This variation in
delay is known as:
A. Latency
B. Jitter
C. Propagation Delay
D. Packet Loss
Rationale: Jitter is the variation in the time between packet
arrivals. High jitter is detrimental to real-time traffic like voice
and video.
15. Which multiplexing technique assigns a specific, fixed time slot to
each user on a channel, regardless of whether the user has data to
send?
A. Synchronous TDM
B. Statistical TDM
C. FDM
D. WDM
Rationale: In Synchronous Time Division Multiplexing, time slots
are pre-assigned and fixed, which can lead to wasted bandwidth
if a user is idle.
AND WIRELESS COMMUNICATIONS
COMPLETE 200 QUESTION MASTER
PRACTICE EXAM
1. Which layer of the OSI model is responsible for logical addressing,
such as IP addresses, and determining the best path for data to
travel?
A. Data Link Layer
B. Network Layer
C. Transport Layer
D. Physical Layer
Rationale: The Network Layer (Layer 3) handles routing and IP
addressing to ensure data reaches the correct destination across
different networks.
2. A network engineer needs a cable that is completely immune to
Electromagnetic Interference (EMI) for a run near high-voltage
machinery. Which should they choose?
A. Cat6a Unshielded Twisted Pair (UTP)
B. RG-6 Coaxial Cable
C. Fiber-optic Cable
D. Cat7 Shielded Twisted Pair (STP)
Rationale: Fiber-optic cables use light pulses rather than
electrical signals, making them entirely immune to EMI and radio
frequency interference.
3. Which technology allows multiple data streams to be sent over a
single high-capacity fiber-optic cable by using different
wavelengths of laser light?
A. Time Division Multiplexing (TDM)
B. Frequency Division Multiplexing (FDM)
C. Dense Wavelength Division Multiplexing (DWDM)
D. Statistical Multiplexing
Rationale: DWDM is a fiber-optic technology that maximizes
bandwidth by multiplexing many signals onto a single fiber using
various wavelengths (colors) of light.
,4. Which 802.11 wireless standard was the first to introduce MIMO
(Multiple-Input Multiple-Output) technology to increase
throughput?
A. 802.11b
B. 802.11g
C. 802.11n
D. 802.11a
Rationale: 802.11n introduced MIMO, using multiple antennas to
send and receive more data simultaneously, significantly
increasing speed and range.
5. An administrator needs to automatically assign IP addresses to
200 new workstations. Which protocol is designed for this task?
A. DNS
B. DHCP
C. SNMP
D. ARP
Rationale: The Dynamic Host Configuration Protocol (DHCP)
automates the process of assigning IP addresses, subnet masks,
and default gateways to devices on a network.
6. Which device operates primarily at the Data Link Layer (Layer 2)
and uses MAC addresses to forward data only to the specific port
where the destination device is connected?
A. Hub
B. Router
C. Switch
D. Repeater
Rationale: Unlike a hub, which broadcasts to everyone, a switch
learns MAC addresses and directs traffic specifically to the
intended recipient.
7. In telecommunications, what is the primary purpose of a
CSU/DSU (Channel Service Unit/Data Service Unit)?
A. To route traffic between different VLANs.
B. To act as a digital interface between a LAN and a high-
speed digital carrier line (like a T1).
C. To convert analog voice to digital VoIP packets.
D. To provide wireless encryption for mobile devices.
Rationale: The CSU/DSU acts as a digital "modem" that converts
data from a router into a format understood by digital leased
lines.
,8. Which modulation technique changes both the amplitude and the
phase of the carrier wave to represent data bits, allowing for higher
data rates?
A. Frequency Shift Keying (FSK)
B. Amplitude Shift Keying (ASK)
C. Quadrature Amplitude Modulation (QAM)
D. Binary Phase Shift Keying (BPSK)
Rationale: QAM is highly efficient because it manipulates two
characteristics of the wave simultaneously, allowing more bits to
be packed into each symbol.
9. A business wants to connect several buildings in a city. Which type
of network is specifically designed for a geographic area the size of
a city or large campus?
A. LAN
B. PAN
C. MAN
D. WAN
Rationale: A Metropolitan Area Network (MAN) spans a city or
large campus, sitting between a local LAN and a global WAN.
10. Which wireless security protocol provides the strongest
encryption and protection against "KRACK" attacks by using a 4-
way handshake?
A. WEP
B. WPA
C. WPA2
D. WPA3
Rationale: WPA3 is the most modern security standard, offering
individualized data encryption and better protection against
brute-force attacks.
11. Which type of signal impairment occurs when a signal loses
strength as it travels further away from the source?
A. Crosstalk
B. Attenuation
C. Dispersion
D. Jitter
Rationale: Attenuation is the natural weakening of a signal over
distance; it is the reason why cables have maximum length limits.
, 12.What is the standard impedance for an RG-6 coaxial cable
commonly used in cable television and satellite installations?
A. 50 ohms
B. 75 ohms
C. 100 ohms
D. 120 ohms
Rationale: RG-6 is designed for video and high-speed internet
applications, which require a 75-ohm impedance to minimize
signal reflection.
13.Which IoT wireless protocol is characterized by low power
consumption and is commonly used in mesh networks for home
automation?
A. Wi-Fi (802.11ac)
B. Zigbee
C. WiMAX
D. LTE
Rationale: Zigbee (802.15.4) is a low-power, short-range wireless
standard ideal for creating mesh networks of smart home devices.
14.A technician is troubleshooting a VoIP call that has inconsistent
delays between packets, causing "choppy" audio. This variation in
delay is known as:
A. Latency
B. Jitter
C. Propagation Delay
D. Packet Loss
Rationale: Jitter is the variation in the time between packet
arrivals. High jitter is detrimental to real-time traffic like voice
and video.
15. Which multiplexing technique assigns a specific, fixed time slot to
each user on a channel, regardless of whether the user has data to
send?
A. Synchronous TDM
B. Statistical TDM
C. FDM
D. WDM
Rationale: In Synchronous Time Division Multiplexing, time slots
are pre-assigned and fixed, which can lead to wasted bandwidth
if a user is idle.
