D413 – Telecommunications and Wireless
Communications – 250 Practice Questions with
Rationales (2026) LATEST UPDATE THIS
YEAR.PDF
Q1
Which of the following best defines telecommunications?
A. The study of computer hardware components
B. The transmission of information over a distance using electronic means
C. The design of software applications for mobile devices
D. The management of local area networks only
Correct answer: B
Rationale: Telecommunications involves transmitting voice, data, video, and other
information over distances using electronic or electromagnetic systems.
Q2
Which component of a telecommunications system is responsible for converting information
into a signal suitable for transmission?
A. Transmission medium
B. Receiver
C. Transmitter
D. Protocol
,Correct answer: C
Rationale: The transmitter converts source information into signals appropriate for the
transmission medium.
Q3
Which of the following is an example of a guided transmission medium?
A. Radio waves
B. Microwaves
C. Fiber-optic cable
D. Infrared
Correct answer: C
Rationale: Guided media physically guide signals (e.g., twisted pair, coaxial, fiber-optic).
Radio, microwave, and infrared are unguided (wireless).
Q4
What is the primary difference between analog and digital signals?
A. Analog signals are discrete; digital signals are continuous
B. Analog signals are continuous; digital signals are discrete
C. Digital signals cannot be amplified
D. Analog signals are more secure
Correct answer: B
,Rationale: Analog signals vary continuously; digital signals use discrete levels (e.g., 0s and
1s).
Q5
Which type of noise is caused by random motion of electrons in a conductor?
A. Impulse noise
B. Crosstalk
C. Thermal noise
D. Intermodulation noise
Correct answer: C
Rationale: Thermal (Johnson) noise results from random electron motion and exists in all
resistive components.
Q6
Which modulation technique varies the amplitude of the carrier wave?
A. Frequency Modulation (FM)
B. Phase Modulation (PM)
C. Amplitude Modulation (AM)
D. Pulse Code Modulation (PCM)
Correct answer: C
Rationale: AM changes the amplitude of the carrier in proportion to the message signal.
, Q7
In digital modulation, which scheme uses two phases separated by 180°?
A. ASK
B. FSK
C. BPSK
D. QAM
Correct answer: C
Rationale: Binary Phase Shift Keying (BPSK) uses two phases (0° and 180°) to represent
binary data.
Q8
Which of the following has the highest frequency range?
A. Radio waves
B. Microwaves
C. Infrared
D. Visible light
Correct answer: D
Rationale: In the electromagnetic spectrum, visible light has higher frequency than infrared,
microwaves, and radio waves.
Q9
What is the primary advantage of digital signals over analog signals in telecommunications?
Communications – 250 Practice Questions with
Rationales (2026) LATEST UPDATE THIS
YEAR.PDF
Q1
Which of the following best defines telecommunications?
A. The study of computer hardware components
B. The transmission of information over a distance using electronic means
C. The design of software applications for mobile devices
D. The management of local area networks only
Correct answer: B
Rationale: Telecommunications involves transmitting voice, data, video, and other
information over distances using electronic or electromagnetic systems.
Q2
Which component of a telecommunications system is responsible for converting information
into a signal suitable for transmission?
A. Transmission medium
B. Receiver
C. Transmitter
D. Protocol
,Correct answer: C
Rationale: The transmitter converts source information into signals appropriate for the
transmission medium.
Q3
Which of the following is an example of a guided transmission medium?
A. Radio waves
B. Microwaves
C. Fiber-optic cable
D. Infrared
Correct answer: C
Rationale: Guided media physically guide signals (e.g., twisted pair, coaxial, fiber-optic).
Radio, microwave, and infrared are unguided (wireless).
Q4
What is the primary difference between analog and digital signals?
A. Analog signals are discrete; digital signals are continuous
B. Analog signals are continuous; digital signals are discrete
C. Digital signals cannot be amplified
D. Analog signals are more secure
Correct answer: B
,Rationale: Analog signals vary continuously; digital signals use discrete levels (e.g., 0s and
1s).
Q5
Which type of noise is caused by random motion of electrons in a conductor?
A. Impulse noise
B. Crosstalk
C. Thermal noise
D. Intermodulation noise
Correct answer: C
Rationale: Thermal (Johnson) noise results from random electron motion and exists in all
resistive components.
Q6
Which modulation technique varies the amplitude of the carrier wave?
A. Frequency Modulation (FM)
B. Phase Modulation (PM)
C. Amplitude Modulation (AM)
D. Pulse Code Modulation (PCM)
Correct answer: C
Rationale: AM changes the amplitude of the carrier in proportion to the message signal.
, Q7
In digital modulation, which scheme uses two phases separated by 180°?
A. ASK
B. FSK
C. BPSK
D. QAM
Correct answer: C
Rationale: Binary Phase Shift Keying (BPSK) uses two phases (0° and 180°) to represent
binary data.
Q8
Which of the following has the highest frequency range?
A. Radio waves
B. Microwaves
C. Infrared
D. Visible light
Correct answer: D
Rationale: In the electromagnetic spectrum, visible light has higher frequency than infrared,
microwaves, and radio waves.
Q9
What is the primary advantage of digital signals over analog signals in telecommunications?
