WGU D413 – Telecommunications & Wireless Communications Objective
Assessment OA V1 and V2 Questions and Answers
SECTION 1: TELECOMMUNICATION & NETWORKING FUNDAMENTALS
Q1. Which OSI layer is responsible for reliable data delivery, error detection, and
retransmission?
A) Network (Layer 3)
B) Transport (Layer 4)
C) Data Link (Layer 2)
D) Session (Layer 5)
Correct Answer: B
Rationale: The Transport layer (e.g., TCP) manages error detection,
retransmission, flow control, and segmentation. Reliability is not handled at the
Network or Data Link layers .
Q2. Which component converts digital signals into analog signals for transmission
over traditional phone lines?
A) Router
B) Switch
C) Modem
,D) Repeater
Correct Answer: C
Rationale: A modem (modulator-demodulator) converts digital data to analog for
transmission over analog phone lines and converts incoming analog signals back
to digital data .
Q3. What is the primary purpose of multiplexing in telecommunications?
A) Error correction
B) Combining multiple signals into one channel
C) Increasing signal strength
D) Encrypting data
Correct Answer: B
Rationale: Multiplexing allows multiple data streams to share a single
transmission medium, improving efficiency and reducing the need for separate
channels .
Q4. Which transmission medium provides the highest bandwidth and lowest
signal loss, while also being immune to electromagnetic interference?
A) Coaxial cable
B) Twisted pair
,C) Fiber-optic cable
D) Microwave
Correct Answer: C
Rationale: Fiber-optic cables transmit data as light, offering extremely high
bandwidth, minimal signal loss over long distances, and complete immunity to
EMI .
Q5. What does latency measure in a network?
A) Error rate
B) Bandwidth
C) Delay in transmission
D) Signal strength
Correct Answer: C
Rationale: Latency is the time delay between sending and receiving data, typically
measured in milliseconds .
Q6. Which communication mode allows simultaneous two-way transmission over
a single link?
A) Simplex
B) Half-duplex
, C) Full-duplex
D) Multiplex
Correct Answer: C
Rationale: Full-duplex communication allows simultaneous bi-directional data
transmission, improving throughput and efficiency (e.g., telephone calls) .
Q7. What is the primary purpose of a subnet mask in IP networking?
A) Encrypt data packets
B) Define which portion of an IP address is the network and which is the host
C) Assign IP addresses automatically
D) Translate domain names to IP addresses
Correct Answer: B
Rationale: Subnet masks divide an IP address into network and host portions,
allowing proper routing and subnetting .
Q8. A network technician needs to divide a network into multiple smaller
segments, each with the same number of hosts. What type of subnetting is being
applied?
A) VLSM (Variable Length Subnet Mask)
B) CIDR (Classless Inter-Domain Routing)
Assessment OA V1 and V2 Questions and Answers
SECTION 1: TELECOMMUNICATION & NETWORKING FUNDAMENTALS
Q1. Which OSI layer is responsible for reliable data delivery, error detection, and
retransmission?
A) Network (Layer 3)
B) Transport (Layer 4)
C) Data Link (Layer 2)
D) Session (Layer 5)
Correct Answer: B
Rationale: The Transport layer (e.g., TCP) manages error detection,
retransmission, flow control, and segmentation. Reliability is not handled at the
Network or Data Link layers .
Q2. Which component converts digital signals into analog signals for transmission
over traditional phone lines?
A) Router
B) Switch
C) Modem
,D) Repeater
Correct Answer: C
Rationale: A modem (modulator-demodulator) converts digital data to analog for
transmission over analog phone lines and converts incoming analog signals back
to digital data .
Q3. What is the primary purpose of multiplexing in telecommunications?
A) Error correction
B) Combining multiple signals into one channel
C) Increasing signal strength
D) Encrypting data
Correct Answer: B
Rationale: Multiplexing allows multiple data streams to share a single
transmission medium, improving efficiency and reducing the need for separate
channels .
Q4. Which transmission medium provides the highest bandwidth and lowest
signal loss, while also being immune to electromagnetic interference?
A) Coaxial cable
B) Twisted pair
,C) Fiber-optic cable
D) Microwave
Correct Answer: C
Rationale: Fiber-optic cables transmit data as light, offering extremely high
bandwidth, minimal signal loss over long distances, and complete immunity to
EMI .
Q5. What does latency measure in a network?
A) Error rate
B) Bandwidth
C) Delay in transmission
D) Signal strength
Correct Answer: C
Rationale: Latency is the time delay between sending and receiving data, typically
measured in milliseconds .
Q6. Which communication mode allows simultaneous two-way transmission over
a single link?
A) Simplex
B) Half-duplex
, C) Full-duplex
D) Multiplex
Correct Answer: C
Rationale: Full-duplex communication allows simultaneous bi-directional data
transmission, improving throughput and efficiency (e.g., telephone calls) .
Q7. What is the primary purpose of a subnet mask in IP networking?
A) Encrypt data packets
B) Define which portion of an IP address is the network and which is the host
C) Assign IP addresses automatically
D) Translate domain names to IP addresses
Correct Answer: B
Rationale: Subnet masks divide an IP address into network and host portions,
allowing proper routing and subnetting .
Q8. A network technician needs to divide a network into multiple smaller
segments, each with the same number of hosts. What type of subnetting is being
applied?
A) VLSM (Variable Length Subnet Mask)
B) CIDR (Classless Inter-Domain Routing)
