AR TC Telecommunications
Contractor Exam Questions And
Correct Answers (Verified Answers)
Plus Rationale2026 Q&A| Instant
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1. What is the standard transmission medium used for high-speed internet
in most telecommunications networks?
A. Coaxial cable
B. Fiber optic cable
C. Twisted pair cable
D. Microwave link
Answer: Fiber optic cable
Rationale: Fiber optic cables offer higher bandwidth and lower
attenuation compared to copper-based cables, making them ideal for
high-speed internet.
2. In telecommunications, what does the acronym PSTN stand for?
A. Public Service Telephone Network
B. Public Switched Telephone Network
C. Private Subscriber Telephone Network
D. Public Satellite Transmission Network
Answer: Public Switched Telephone Network
Rationale: PSTN is the traditional circuit-switched telephone
network used for voice communication worldwide.
3. Which frequency band is commonly used for mobile 4G LTE
networks?
A. 300–400 MHz
B. 700–2600 MHz
, C. 5–6 GHz
D. 10–12 GHz
Answer: 700–2600 MHz
Rationale: 4G LTE networks operate mainly in the 700 MHz to 2600
MHz range, balancing coverage and capacity.
4. What type of cable is most susceptible to electromagnetic interference
(EMI)?
A. Fiber optic cable
B. Twisted pair copper cable
C. Coaxial cable
D. Shielded twisted pair
Answer: Twisted pair copper cable
Rationale: Unshielded twisted pair (UTP) cables are prone to EMI,
whereas coaxial and fiber optic cables are better shielded or immune.
5. Which device is used to amplify signals in long-distance fiber optic
networks?
A. Router
B. Switch
C. Optical repeater
D. Multiplexer
Answer: Optical repeater
Rationale: Optical repeaters regenerate the signal to prevent loss in
long-distance fiber optic networks.
6. In a star topology network, all devices are connected to a:
A. Ring
B. Bus
C. Central hub or switch
D. Mesh network
Answer: Central hub or switch
Rationale: Star topology connects all nodes to a central device for
easier management and isolation of faults.
7. What does VoIP stand for in telecommunications?
A. Voice over Internet Protocol
B. Voice on Internal Phone
C. Video over Internet Protocol
D. Voice over Internet Protocol
Answer: Voice over Internet Protocol
, Rationale: VoIP allows voice communication over IP networks
instead of traditional circuit-switched telephony.
8. What is the main purpose of a multiplexing system?
A. Increase signal noise
B. Combine multiple signals into one transmission channel
C. Convert analog signals to digital
D. Isolate signals
Answer: Combine multiple signals into one transmission channel
Rationale: Multiplexing allows efficient use of bandwidth by
combining multiple signals into a single transmission path.
9. In telecommunications, what is the purpose of a demultiplexer?
A. Amplify signals
B. Convert digital to analog
C. Separate combined signals into individual channels
D. Encrypt data
Answer: Separate combined signals into individual channels
Rationale: A demultiplexer performs the reverse of multiplexing by
separating signals back into distinct streams.
10. Which protocol is commonly used for sending emails over the
internet?
A. FTP
B. HTTP
C. SMTP
D. SNMP
Answer: SMTP
Rationale: Simple Mail Transfer Protocol (SMTP) is the standard
protocol for email transmission.
11. Which component connects different networks together and
routes data packets?
A. Hub
B. Router
C. Switch
D. Modem
Answer: Router
Rationale: Routers direct data between networks and manage IP
addressing.
Contractor Exam Questions And
Correct Answers (Verified Answers)
Plus Rationale2026 Q&A| Instant
Download Pdf
1. What is the standard transmission medium used for high-speed internet
in most telecommunications networks?
A. Coaxial cable
B. Fiber optic cable
C. Twisted pair cable
D. Microwave link
Answer: Fiber optic cable
Rationale: Fiber optic cables offer higher bandwidth and lower
attenuation compared to copper-based cables, making them ideal for
high-speed internet.
2. In telecommunications, what does the acronym PSTN stand for?
A. Public Service Telephone Network
B. Public Switched Telephone Network
C. Private Subscriber Telephone Network
D. Public Satellite Transmission Network
Answer: Public Switched Telephone Network
Rationale: PSTN is the traditional circuit-switched telephone
network used for voice communication worldwide.
3. Which frequency band is commonly used for mobile 4G LTE
networks?
A. 300–400 MHz
B. 700–2600 MHz
, C. 5–6 GHz
D. 10–12 GHz
Answer: 700–2600 MHz
Rationale: 4G LTE networks operate mainly in the 700 MHz to 2600
MHz range, balancing coverage and capacity.
4. What type of cable is most susceptible to electromagnetic interference
(EMI)?
A. Fiber optic cable
B. Twisted pair copper cable
C. Coaxial cable
D. Shielded twisted pair
Answer: Twisted pair copper cable
Rationale: Unshielded twisted pair (UTP) cables are prone to EMI,
whereas coaxial and fiber optic cables are better shielded or immune.
5. Which device is used to amplify signals in long-distance fiber optic
networks?
A. Router
B. Switch
C. Optical repeater
D. Multiplexer
Answer: Optical repeater
Rationale: Optical repeaters regenerate the signal to prevent loss in
long-distance fiber optic networks.
6. In a star topology network, all devices are connected to a:
A. Ring
B. Bus
C. Central hub or switch
D. Mesh network
Answer: Central hub or switch
Rationale: Star topology connects all nodes to a central device for
easier management and isolation of faults.
7. What does VoIP stand for in telecommunications?
A. Voice over Internet Protocol
B. Voice on Internal Phone
C. Video over Internet Protocol
D. Voice over Internet Protocol
Answer: Voice over Internet Protocol
, Rationale: VoIP allows voice communication over IP networks
instead of traditional circuit-switched telephony.
8. What is the main purpose of a multiplexing system?
A. Increase signal noise
B. Combine multiple signals into one transmission channel
C. Convert analog signals to digital
D. Isolate signals
Answer: Combine multiple signals into one transmission channel
Rationale: Multiplexing allows efficient use of bandwidth by
combining multiple signals into a single transmission path.
9. In telecommunications, what is the purpose of a demultiplexer?
A. Amplify signals
B. Convert digital to analog
C. Separate combined signals into individual channels
D. Encrypt data
Answer: Separate combined signals into individual channels
Rationale: A demultiplexer performs the reverse of multiplexing by
separating signals back into distinct streams.
10. Which protocol is commonly used for sending emails over the
internet?
A. FTP
B. HTTP
C. SMTP
D. SNMP
Answer: SMTP
Rationale: Simple Mail Transfer Protocol (SMTP) is the standard
protocol for email transmission.
11. Which component connects different networks together and
routes data packets?
A. Hub
B. Router
C. Switch
D. Modem
Answer: Router
Rationale: Routers direct data between networks and manage IP
addressing.
