1. What is attenuation in the context of data transmission?

a) Increase in signal strength over distance

b) Decrease in signal strength over distance
c) Variability in signal arrival times
d) Compression of data signals
Answer: b) Decrease in signal strength over distance

2. Which factor does NOT contribute to signal attenuation?

a) Distance
b) Interference
c) Signal frequency
d) Error correction techniques
Answer: d) Error correction techniques

3. What is the primary medium used in FDDI networks?

a) Copper cables
b) Coaxial cables
c) Fiber optic cables
d) Wireless signals
Answer: c) Fiber optic cables

4. What is the maximum distance between two nodes in an FDDI network?

a) 2 km
b) 10 km
c) 100 km
d) 200 km
Answer: b) 10 km

5. What topology does FDDI use to provide redundancy?

a) Star topology
b) Bus topology
c) Ring topology
d) Mesh topology
Answer: c) Ring topology

6. What is noise in the context of data transmission?

a) An increase in signal strength
b) Random electrical signals that interfere with data transmission
c) A method of data compression
d) A technique for improving signal clarity
Answer: b) Random electrical signals that interfere with data transmission
7. Which type of noise is caused by thermal agitation of electrons?
a) Impulse noise
b) Crosstalk
c) Thermal noise
d) Intermodulation noise
Answer: c) Thermal noise

8. What is crosstalk in data transmission?

a) Noise generated by other electronic devices
b) Noise caused by interference between adjacent wires or cables
c) Random electromagnetic interference
d) Noise from environmental sources
Answer: b) Noise caused by interference between adjacent wires or cables

9. Which factor does NOT typically contribute to signal attenuation in a transmission medium?
a) Distance
b) Frequency
c) Signal power
d) Temperature
Answer: d) Temperature

10. How can signal attenuation be reduced in a transmission medium?

a) By increasing the distance between transmitter and receiver
b) By increasing the transmission power
c) By using higher frequency signals
d) By adding noise to the signal
Answer: b) By increasing the transmission power

11. Which type of cable is most susceptible to attenuation over long distances?
a) Fiber optic cable
b) Coaxial cable
c) Twisted pair cable
d) Shielded twisted pair cable
Answer: c) Twisted pair cable

12. What is the relationship between signal frequency and attenuation in a transmission medium?
a) Higher frequency signals experience less attenuation
b) Lower frequency signals experience more attenuation
c) Higher frequency signals experience more attenuation
d) Frequency does not affect attenuation
Answer: c) Higher frequency signals experience more attenuation
13. What is a signal in the context of data communication?
a) A type of software application
b) A method of encoding data
c) A representation of data using electrical or electromagnetic waves
d) A storage device for data
Answer: c) A representation of data using electrical or electromagnetic waves

14. What is the primary purpose of a signal in data communication?

a) To store data
b) To transmit data
c) To encrypt data
d) To compress data
Answer: b) To transmit data

15. Which of the following is a characteristic of an analog signal?

a) Discrete values
b) Continuous values
c) Binary representation
d) Error-free transmission
Answer: b) Continuous values

16. Which type of signal is typically used in modern computer networks?

a) Analog signals
b) Digital signals
c) Continuous signals
d) Electromagnetic signals
Answer: b) Digital signals

17. What is one advantage of digital signals over analog signals?

a) Lower cost
b) Simplicity of generation
c) Better noise immunity and error correction
d) Higher frequency range
Answer: c) Better noise immunity and error correction

18. What does the bit rate of a communication channel indicate?

a) The maximum distance data can travel
b) The amount of data transmitted per unit time
c) The number of signal changes per second
d) The error rate of the transmission
Answer: b) The amount of data transmitted per unit time
19. What does the baud rate of a communication channel indicate?
a) The maximum distance data can travel
b) The amount of data transmitted per unit time
c) The number of signal changes or symbols transmitted per second
d) The error rate of the transmission
Answer: c) The number of signal changes or symbols transmitted per second

20. If a communication system has a bit rate of 2400 bps and a baud rate of 600 baud, how many bits are
transmitted per symbol?
a) 2 bits per symbol
b) 3 bits per symbol
c) 4 bits per symbol
d) 6 bits per symbol
Answer: c) 4 bits per symbol

21. In the context of data transmission, what is the primary difference between bit rate and baud rate?
a) Bit rate measures data speed; baud rate measures error rate
b) Bit rate measures signal changes per second; baud rate measures data speed
c) Bit rate measures data speed; baud rate measures signal changes per second
d) Bit rate measures error rate; baud rate measures data speed
Answer: c) Bit rate measures data speed; baud rate measures signal changes per second

22. What is the relationship between the frequency of a signal and its wavelength?
a) Directly proportional
b) Inversely proportional
c) No relationship
d) Exponentially proportional
Answer: b) Inversely proportional

23. Which modulation technique is used to encode digital data onto an analog signal by varying the
amplitude of the carrier wave?
a) Frequency modulation (FM)
b) Phase modulation (PM)
c) Amplitude modulation (AM)
d) Quadrature amplitude modulation (QAM)
Answer: c) Amplitude modulation (AM)

24. Which type of signal is more susceptible to noise and distortion over long distances?
a) Digital signals
b) Analog signals
c) Both digital and analog signals equally
d) Neither digital nor analog signals
Answer: b) Analog signals
25. What type of signal can be described as a series of pulses representing binary data?
a) Analog signal
b) Digital signal
c) Electromagnetic signal
d) Optical signal
Answer: b) Digital signal

26. Which of the following is NOT a typical use of analog signals?

a) Voice transmission over traditional telephone lines
b) Audio recording on vinyl records
c) Data transmission in computer networks
d) Broadcasting AM/FM radio
Answer: c) Data transmission in computer networks

27. Which conversion process involves changing an analog signal to a digital signal?
a) Modulation
b) Demodulation
c) Analog-to-digital conversion (ADC)
d) Digital-to-analog conversion (DAC)
Answer: c) Analog-to-digital conversion (ADC)

28. Which of the following is a disadvantage of digital signals compared to analog signals?
a) Lower noise immunity
b) Higher susceptibility to interference
c) Higher bandwidth requirement
d) Less accurate representation of continuous signals
Answer: c) Higher bandwidth requirement

29. In which scenario would you prefer using an analog signal over a digital signal?
a) High-fidelity audio recording
b) Long-distance data transmission
c) Computer networking
d) Digital television broadcasting
Answer: a) High-fidelity audio recording

30. If a communication channel has a baud rate of 1000 baud and each symbol carries 8 bits, what is the
bit rate?
a) 800 bps
b) 1000 bps
c) 8000 bps
d) 10000 bps
Answer: c) 8000 bps
31. What term describes the maximum rate at which data can be transmitted over a communication
channel without errors?
a) Bandwidth
b) Bit rate
c) Baud rate
d) Throughput
Answer: a) Bandwidth

32. Which of the following factors directly affects the baud rate of a communication system?
a) Signal frequency
b) Signal amplitude
c) Symbol duration
d) Signal phase
Answer: c) Symbol duration

33. What is the relationship between signal-to-noise ratio (SNR) and data transmission quality?
a) Higher SNR results in lower transmission quality
b) Higher SNR results in higher transmission quality
c) SNR has no effect on transmission quality
d) Lower SNR results in higher transmission quality
Answer: b) Higher SNR results in higher transmission quality

34. What is the typical use of amplitude shift keying (ASK) in digital communication?
a) Modulating analog signals
b) Modulating digital signals
c) Demodulating analog signals
d) Demodulating digital signals
Answer: b) Modulating digital signals

35. In which type of communication is pulse code modulation (PCM) commonly used?
a) Analog voice transmission
b) Digital voice transmission
c) Analog video transmission
d) Digital video transmission
Answer: b) Digital voice transmission

36. What does the Nyquist theorem state about sampling rate?
a) The sampling rate must be twice the highest frequency of the analog signal
b) The sampling rate must be equal to the highest frequency of the analog signal
c) The sampling rate must be half the highest frequency of the analog signal
d) The sampling rate is unrelated to the highest frequency of the analog signal
Answer: a) The sampling rate must be twice the highest frequency of the analog signal
37. What is the term for a continuous signal that varies over time and can take on any value in a given
range?
a) Discrete signal
b) Analog signal
c) Digital signal
d) Pulse signal
Answer: b) Analog signal

38. Which of the following describes a digital signal?

a) A signal that can have any value in a continuous range
b) A signal that represents data as a series of discrete values
c) A signal used only in analog communications
d) A signal with infinite bandwidth
Answer: b) A signal that represents data as a series of discrete values

39. In an analog signal, what does the amplitude represent?

a) The height of the wave
b) The width of the wave
c) The frequency of the wave
d) The phase of the wave
Answer: a) The height of the wave

40. Which device is used to convert digital signals into analog signals for transmission over traditional
telephone lines?
a) Modem
b) Router
c) Switch
d) Hub
Answer: a) Modem

41. If a digital communication system transmits data at a bit rate of 4800 bps and each signal change
represents 2 bits, what is the baud rate?
a) 1200 baud
b) 2400 baud
c) 4800 baud
d) 9600 baud
Answer: b) 2400 baud

42. Which parameter measures the amount of data transmitted per second in a communication system?
a) Bandwidth
b) Bit rate
c) Baud rate
d) Frequency
Answer: b) Bit rate
43. What is the relationship between baud rate and bit rate in a system where each symbol represents
multiple bits?
a) Baud rate is equal to bit rate
b) Baud rate is higher than bit rate
c) Baud rate is lower than bit rate
d) Baud rate and bit rate are unrelated
Answer: c) Baud rate is lower than bit rate

44. What is the purpose of using modulation in data communication?

a) To amplify the signal
b) To reduce signal attenuation
c) To transmit data over a specific medium
d) To store data
Answer: c) To transmit data over a specific medium

45. Which modulation technique involves varying the frequency of the carrier wave to encode data?
a) Amplitude modulation (AM)
b) Frequency modulation (FM)
c) Phase modulation (PM)
d) Quadrature amplitude modulation (QAM)
Answer: b) Frequency modulation (FM)

46. What is quantization in the context of analog-to-digital conversion?

a) The process of filtering noise from an analog signal
b) The process of sampling an analog signal at regular intervals
c) The process of converting continuous signal values into discrete levels
d) The process of encoding data into a carrier wave
Answer: c) The process of converting continuous signal values into discrete levels

47. What does a higher bit depth in digital audio recording signify?
a) Higher frequency range
b) Higher sampling rate
c) More detailed representation of the audio signal
d) Faster data transmission
Answer: c) More detailed representation of the audio signal

48. Which type of noise is caused by sudden, short bursts of energy and can severely disrupt
communication?
a) Thermal noise
b) Impulse noise
c) Crosstalk
d) Intermodulation noise
Answer: b) Impulse noise
49. What is the main advantage of using fiber optic cables over copper cables for data transmission?
a) Lower cost
b) Greater flexibility
c) Higher data transmission rates and longer distances
d) Easier installation
Answer: c) Higher data transmission rates and longer distances

50. In a communication system, what is the effect of increasing the signal-to-noise ratio (SNR)?
a) Increased signal attenuation
b) Increased data transmission errors
c) Improved data transmission quality
d) Decreased bandwidth
Answer: c) Improved data transmission quality