Q441. What does the term “digital signal” refer to?
A) A signal with a continuous range of frequencies
B) A signal represented by discrete binary values
C) A signal that can vary in amplitude and frequency
D) A signal that is transmitted over analog media
✅ Correct Answer: B

Q442. What is the main function of a “hub” in data communication?
A) To route data between different networks
B) To amplify the signal and extend transmission distance
C) To distribute data to all devices in a network
D) To secure data transmissions with encryption
✅ Correct Answer: C

Q443. Which of the following is a disadvantage of using “satellite communication”?
A) Higher latency due to long distance
B) Better signal quality
C) Faster transmission speeds
D) Less expensive than fiber-optic cables
✅ Correct Answer: A

Q444. In a data communication system, what does “modulation” do?
A) Converts data into a format that can be transmitted
B) Converts digital signals into analog signals
C) Increases the bandwidth of the signal
D) Reduces the noise in the signal
✅ Correct Answer: B

Q445. Which of the following types of communication allows data to flow in both directions at the same time?
A) Simplex
B) Half-duplex
C) Full-duplex
D) Bi-directional
✅ Correct Answer: C

Q446. In data communication, what does “signal attenuation” refer to?
A) The process of amplifying the signal
B) The loss of signal strength over distance
C) The time delay in signal transmission
D) The encryption of transmitted data
✅ Correct Answer: B

Q447. Which of the following is an example of a “baseband” transmission system?
A) AM radio
B) Ethernet
C) Wi-Fi
D) TV broadcasting
✅ Correct Answer: B

Q448. What is the primary advantage of using “fiber optic cables” over copper cables in data communication?
A) Less expensive
B) Higher data transfer speed and less interference
C) Easier to install
D) Higher power consumption
✅ Correct Answer: B

Q449. Which of the following transmission modes is used for one-way communication only?
A) Full-duplex
B) Half-duplex
C) Simplex
D) Duplex
✅ Correct Answer: C

Q450. In a data communication system, what is the primary role of “encoding”?
A) To convert digital data into a form suitable for transmission
B) To ensure that data is encrypted before transmission
C) To compress the data for faster transmission
D) To decode the received data
✅ Correct Answer: A

Q451. What does the “Nyquist theorem” help determine in data communication?
A) The maximum signal frequency for data transmission
B) The maximum number of devices on a network
C) The maximum data rate that can be transmitted over a given bandwidth
D) The ideal data transmission medium
✅ Correct Answer: C

Q452. Which of the following is the standard protocol used for error checking in data communication?
A) FTP
B) CRC (Cyclic Redundancy Check)
C) HTTP
D) IP
✅ Correct Answer: B

Q453. Which of the following best describes “packet switching” in data communication?
A) Data is transmitted in a continuous stream with no breaks
B) Data is divided into packets and each packet is routed independently
C) Data is sent in the form of a single large chunk
D) Data is first compressed and then transmitted
✅ Correct Answer: B

Q454. Which of the following is the primary function of “error correction” in data communication?
A) To detect and correct errors in transmitted data
B) To encrypt the data during transmission
C) To increase the bandwidth of the communication channel
D) To compress data for efficient transmission
✅ Correct Answer: A

Q455. In data communication, what is the “physical layer” responsible for?
A) Routing data between networks
B) Error detection and correction
C) Encoding data into electrical or optical signals
D) Providing end-to-end communication
✅ Correct Answer: C

Q456. Which of the following modulation techniques is used to transmit digital data over analog media?
A) Frequency Modulation (FM)
B) Phase Modulation (PM)
C) Amplitude Modulation (AM)
D) Quadrature Amplitude Modulation (QAM)
✅ Correct Answer: D

Q457. What is the term “bit rate” used to describe in data communication?
A) The frequency of the signal
B) The distance the signal can travel
C) The number of bits transmitted per unit of time
D) The number of devices in the network
✅ Correct Answer: C

Q458. Which of the following devices is primarily responsible for connecting different networks together?
A) Hub
B) Router
C) Switch
D) Repeater
✅ Correct Answer: B

Q459. Which of the following is a primary characteristic of “half-duplex” communication?
A) Data can travel in both directions at the same time
B) Data can travel in one direction at a time
C) Data can travel in one direction, but not at the same time
D) It only supports analog signals
✅ Correct Answer: C

Q460. What does the term “frequency” refer to in data communication?
A) The amount of data transmitted in a given time
B) The number of times a signal oscillates per second
C) The distance between the sender and the receiver
D) The amount of noise in the signal
✅ Correct Answer: B

Q461. What does the term “latency” refer to in data communication?
A) The number of packets transmitted in a given time
B) The time delay between sending and receiving a message
C) The loss of data during transmission
D) The speed of the transmission medium
✅ Correct Answer: B

Q462. What is the primary function of a “repeater” in a data communication system?
A) To route data between different networks
B) To amplify or regenerate signals to extend their reach
C) To convert digital signals into analog signals
D) To manage the flow of data between devices
✅ Correct Answer: B

Q463. Which of the following is an example of an analog transmission?
A) Ethernet
B) Radio transmission
C) USB
D) Fiber optics
✅ Correct Answer: B

Q464. In data communication, what does “signal encoding” mean?
A) Converting data into a format suitable for transmission
B) Compressing data for faster transmission
C) Encrypting data for security
D) Detecting errors in the transmitted data
✅ Correct Answer: A

Q465. Which of the following transmission media is least susceptible to interference?
A) Coaxial cable
B) Twisted pair cable
C) Fiber optic cable
D) Wireless transmission
✅ Correct Answer: C

Q466. What is the primary difference between “analog” and “digital” communication?
A) Analog communication uses continuous signals, while digital uses discrete signals
B) Analog communication uses binary signals, while digital uses continuous signals
C) Analog communication is faster than digital communication
D) Digital communication is more susceptible to noise than analog communication
✅ Correct Answer: A

Q467. Which layer of the OSI model is responsible for providing reliable, end-to-end communication?
A) Application layer
B) Transport layer
C) Data link layer
D) Physical layer
✅ Correct Answer: B

Q468. In data communication, what is the primary role of the “data link layer”?
A) Routing packets between different networks
B) Providing error detection and correction
C) Encrypting data during transmission
D) Managing the physical transmission of data
✅ Correct Answer: B

Q469. What is “frequency modulation” used for in data communication?
A) To modulate the frequency of the carrier signal to carry data
B) To reduce the amplitude of the signal
C) To convert analog signals to digital signals
D) To compress the data for faster transmission
✅ Correct Answer: A

Q470. What is the term “bit error rate” (BER) used to measure in a data communication system?
A) The speed of data transmission
B) The ratio of errors to the total number of bits transmitted
C) The bandwidth of the transmission channel
D) The latency in the network
✅ Correct Answer: B

Q471. Which of the following is true about “coaxial cables”?
A) They are the fastest transmission medium
B) They are more susceptible to electromagnetic interference than fiber optic cables
C) They are primarily used for short-distance communication
D) They consist of a central conductor, an insulating layer, a metallic shield, and an outer insulating layer
✅ Correct Answer: D

Q472. In data communication, what does “propagation delay” refer to?
A) The time taken for the signal to travel from the sender to the receiver
B) The loss of signal during transmission
C) The delay due to encoding and decoding of data
D) The time taken to process the data
✅ Correct Answer: A

Q473. Which of the following is an example of a “guided transmission medium”?
A) Radio waves
B) Satellite communication
C) Fiber optic cables
D) Wi-Fi
✅ Correct Answer: C

Q474. What is the primary disadvantage of using “twisted pair cables” for data transmission?
A) They are expensive
B) They have a high susceptibility to electromagnetic interference
C) They provide lower data transfer speeds than fiber optics
D) They are not flexible
✅ Correct Answer: B

Q475. What is the purpose of “forward error correction” in data communication?
A) To detect errors and request retransmission
B) To reduce the data size for efficient transmission
C) To correct errors in data without requiring retransmission
D) To compress the data for faster transmission
✅ Correct Answer: C

Q476. In data communication, what is the term “baud rate” used to describe?
A) The number of bits transmitted per second
B) The number of symbols transmitted per second
C) The time delay between sending and receiving data
D) The bandwidth of the communication channel
✅ Correct Answer: B

Q477. What does the term “modem” stand for?
A) Modulator-Demodulator
B) Maximum Data Exchange
C) Multiplexer-Decoder
D) Medium Data Encoder-Decoder
✅ Correct Answer: A

Q478. In data communication, what is “multiplexing”?
A) Encrypting data to make it secure for transmission
B) Dividing a communication channel into multiple sub-channels
C) Compressing data to reduce the transmission time
D) Sending data in a single continuous stream
✅ Correct Answer: B

Q479. Which of the following is a feature of “Wi-Fi” communication?
A) It uses fiber optic cables for communication
B) It operates over short-range radio frequencies
C) It has a higher data transfer rate than Ethernet
D) It is a type of analog communication
✅ Correct Answer: B

Q480. Which of the following protocols is commonly used for secure communication over the internet?
A) HTTP
B) FTP
C) HTTPS
D) SMTP
✅ Correct Answer: C

Q481. Which of the following transmission modes allows data to travel in only one direction?
A) Full-duplex
B) Half-duplex
C) Simplex
D) Bi-directional
✅ Correct Answer: C

Q482. What is the maximum distance that a typical coaxial cable can transmit data?
A) 100 meters
B) 500 meters
C) 2 kilometers
D) 50 kilometers
✅ Correct Answer: A

Q483. What does “QAM” stand for in data communication?
A) Quality of Access Modulation
B) Quadrature Amplitude Modulation
C) Quick Amplitude Modulation
D) Quantitative Amplitude Modulation
✅ Correct Answer: B

Q484. Which of the following is an example of a wireless transmission technology?
A) USB
B) Bluetooth
C) Fiber optic cables
D) Coaxial cables
✅ Correct Answer: B

Q485. What is the main purpose of a “modulator” in a data communication system?
A) To reduce signal interference
B) To encode the data into a suitable form for transmission
C) To decode received signals
D) To amplify the transmitted signal
✅ Correct Answer: B

Q486. Which of the following is an example of a digital communication system?
A) AM radio
B) Wi-Fi
C) Television broadcasting
D) Analog telephone lines
✅ Correct Answer: B

Q487. What is the name of the error detection method that uses parity bits?
A) Hamming code
B) Checksum
C) CRC (Cyclic Redundancy Check)
D) Parity checking
✅ Correct Answer: D

Q488. In a data communication system, what is “jitter” used to describe?
A) The variation in signal strength
B) The variation in packet arrival times
C) The maximum range of signal transmission
D) The amount of data transmitted per second
✅ Correct Answer: B

Q489. What is the purpose of the “Network Interface Card” (NIC) in a computer?
A) To convert digital signals to analog signals
B) To connect the computer to a local network
C) To route packets between different networks
D) To amplify the transmitted signal
✅ Correct Answer: B

Q490. What does the “physical layer” in the OSI model deal with?
A) Logical addressing
B) Data encryption
C) Transmission of raw data bits over a communication channel
D) Routing of data packets
✅ Correct Answer: C

Q491. Which of the following is a limitation of wireless communication compared to wired communication?
A) Lower latency
B) Higher signal strength
C) Greater susceptibility to interference
D) Higher data transfer rates
✅ Correct Answer: C

Q492. In the context of fiber optic communication, what does “total internal reflection” refer to?
A) The reflection of light inside the core of the fiber
B) The absorption of light by the fiber
C) The transmission of light through the fiber’s cladding
D) The bending of light at the fiber’s surface
✅ Correct Answer: A

Q493. Which of the following protocols is used for dynamic IP address assignment in a network?
A) DNS
B) FTP
C) DHCP
D) SNMP
✅ Correct Answer: C

Q494. What does the term “bit” refer to in data communication?
A) A single unit of information, represented by 1 or 0
B) A packet of data transmitted over the network
C) The frequency of the signal
D) The number of devices connected to the network
✅ Correct Answer: A

Q495. What is the term “bandwidth” used to describe in data communication?
A) The number of data bits transmitted per second
B) The range of frequencies available for data transmission
C) The time it takes for data to travel from sender to receiver
D) The number of errors in the transmitted signal
✅ Correct Answer: B

Q496. In data communication, which of the following best describes “modem”?
A) A device that encrypts data for secure transmission
B) A device that converts digital data to analog signals and vice versa
C) A device that routes packets between networks
D) A device used for signal amplification
✅ Correct Answer: B

Q497. What is the primary purpose of “data compression” in communication?
A) To increase the size of the transmitted data
B) To reduce the amount of data transmitted
C) To encrypt data for security
D) To detect and correct errors in data
✅ Correct Answer: B

Q498. Which of the following is the maximum transmission speed of an IEEE 802.11ac (Wi-Fi 5) connection?
A) 54 Mbps
B) 1 Gbps
C) 5 Gbps
D) 10 Gbps
✅ Correct Answer: C

Q499. What is the primary role of the “transport layer” in the OSI model?
A) To ensure reliable data transfer between two devices
B) To define the physical transmission medium
C) To provide error-free transmission over a communication channel
D) To handle end-to-end communication and flow control
✅ Correct Answer: A

Q500. Which of the following devices operates at the “Data Link” layer of the OSI model?
A) Router
B) Switch
C) Hub
D) Repeater
✅ Correct Answer: B