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WGU D315 Network and Security Foundations
OA Exam – Complete 400 Questions with
Verified Answers
Official Exam Overview:
The WGU D315 Network and Security Foundations Objective Assessment evaluates learners’
knowledge of network concepts, security principles, and foundational IT practices. The exam
emphasizes the design, implementation, and protection of network systems and the
understanding of hardware, protocols, and data transmission methods.
Exam Coverage Areas:
• Network Architecture and Components
• Data Transmission and Cabling
• Network Protocols and Standards
• Security Principles and Best Practices
• Troubleshooting and Maintenance
• Optical Fiber and Wireless Communication
• Network Monitoring and Management
• Multiple Choice and Short Answer Question Formats
QUESTION 1: What part of an optical fiber carries the light?
a) Cladding
b) Jacket
c) Core ✅
d) Connector
Rationale: The core of an optical fiber is the central region that transmits light signals, while the
cladding surrounds it to reflect the light back into the core and the jacket provides protection.
QUESTION 2: Which device is primarily used to connect multiple network segments and direct
data between them?
a) Hub
b) Switch ✅
c) Modem
d) Access Point
Rationale: A switch connects multiple devices within a network and directs data to the correct
destination using MAC addresses.
,QUESTION 3: Which layer of the OSI model is responsible for routing data between networks?
a) Physical
b) Data Link
c) Network ✅
d) Transport
Rationale: The Network layer manages logical addressing and routing of data packets across
different networks.
QUESTION 4: Which security principle involves ensuring that data is accessible only to
authorized users?
a) Integrity
b) Availability
c) Confidentiality ✅
d) Non-repudiation
Rationale: Confidentiality ensures that sensitive information is protected from unauthorized
access.
QUESTION 5: What type of network cable uses light to transmit data?
a) Coaxial
b) Twisted Pair
c) Optical Fiber ✅
d) Ethernet
Rationale: Optical fiber cables transmit data using pulses of light, allowing high-speed, long-
distance communication.
Q: What part of an optical fiber carries the light - ANSWER-the core of an optical fiber carries
the light
Q: What is a measure of fibers light acceptance - ANSWER-numerical aperture
Q: typical core/cladding sizes in microns for multimode fiber - ANSWER-50/125um and
62.5/125um
Q: Typical core size for single fiber mode - ANSWER-7 to 10 um
Q: what are the two key distance limiting parameters in fiber optic transmission - ANSWER-
,attenuation and dispersion
Q: four factors that contribute to attenuation - ANSWER-scattering, absorbtion, macrobending,
microbending
Q: three types of dispersion - ANSWER-modal, chromatic, polorazation mode
Q: two light sources used in fiber optic - ANSWER-diode laser
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light emitting diode
Q: max length of multimode fiber - ANSWER-2km
Q: max length of single mode fiber - ANSWER-80km
Q: EIA - ANSWER-electronics industries alliance
Q: TIA - ANSWER-Telecommunications industry association
Q: six subsystems of a structured cabling system - ANSWER-building entrance
equipment room
backbone cabling
telecom closet
horizontal cabling
work area
Basic elements of a fiber-optic communication plan - ANSWER-fiber, optical light source,
photosensitice detection, efficient optical connection
Q: Advantages of fiber optics - ANSWER-bandwidth
immunity to electrostatic interference
elimination of crosstalk
lower signal attenuation
2
WGU D315 Network and Security Foundations
OA Exam – Complete 400 Questions with
Verified Answers
Official Exam Overview:
The WGU D315 Network and Security Foundations Objective Assessment evaluates learners’
knowledge of network concepts, security principles, and foundational IT practices. The exam
emphasizes the design, implementation, and protection of network systems and the
understanding of hardware, protocols, and data transmission methods.
Exam Coverage Areas:
• Network Architecture and Components
• Data Transmission and Cabling
• Network Protocols and Standards
• Security Principles and Best Practices
• Troubleshooting and Maintenance
• Optical Fiber and Wireless Communication
• Network Monitoring and Management
• Multiple Choice and Short Answer Question Formats
QUESTION 1: What part of an optical fiber carries the light?
a) Cladding
b) Jacket
c) Core ✅
d) Connector
Rationale: The core of an optical fiber is the central region that transmits light signals, while the
cladding surrounds it to reflect the light back into the core and the jacket provides protection.
QUESTION 2: Which device is primarily used to connect multiple network segments and direct
data between them?
a) Hub
b) Switch ✅
c) Modem
d) Access Point
Rationale: A switch connects multiple devices within a network and directs data to the correct
destination using MAC addresses.
,QUESTION 3: Which layer of the OSI model is responsible for routing data between networks?
a) Physical
b) Data Link
c) Network ✅
d) Transport
Rationale: The Network layer manages logical addressing and routing of data packets across
different networks.
QUESTION 4: Which security principle involves ensuring that data is accessible only to
authorized users?
a) Integrity
b) Availability
c) Confidentiality ✅
d) Non-repudiation
Rationale: Confidentiality ensures that sensitive information is protected from unauthorized
access.
QUESTION 5: What type of network cable uses light to transmit data?
a) Coaxial
b) Twisted Pair
c) Optical Fiber ✅
d) Ethernet
Rationale: Optical fiber cables transmit data using pulses of light, allowing high-speed, long-
distance communication.
Q: What part of an optical fiber carries the light - ANSWER-the core of an optical fiber carries
the light
Q: What is a measure of fibers light acceptance - ANSWER-numerical aperture
Q: typical core/cladding sizes in microns for multimode fiber - ANSWER-50/125um and
62.5/125um
Q: Typical core size for single fiber mode - ANSWER-7 to 10 um
Q: what are the two key distance limiting parameters in fiber optic transmission - ANSWER-
,attenuation and dispersion
Q: four factors that contribute to attenuation - ANSWER-scattering, absorbtion, macrobending,
microbending
Q: three types of dispersion - ANSWER-modal, chromatic, polorazation mode
Q: two light sources used in fiber optic - ANSWER-diode laser
1
, Page 2 of 174
light emitting diode
Q: max length of multimode fiber - ANSWER-2km
Q: max length of single mode fiber - ANSWER-80km
Q: EIA - ANSWER-electronics industries alliance
Q: TIA - ANSWER-Telecommunications industry association
Q: six subsystems of a structured cabling system - ANSWER-building entrance
equipment room
backbone cabling
telecom closet
horizontal cabling
work area
Basic elements of a fiber-optic communication plan - ANSWER-fiber, optical light source,
photosensitice detection, efficient optical connection
Q: Advantages of fiber optics - ANSWER-bandwidth
immunity to electrostatic interference
elimination of crosstalk
lower signal attenuation
2
