TRB PG Assistant - Transmission Techniques - data encoding, modulation, broadband and baseband transmission, multiplexing, transmission media, error handling mechanisms Online Test (MCQ Quiz)

1. Which of the following is a digital-to-analog encoding technique?

A) Manchester Encoding B) NRZ-L C) ASK (Amplitude Shift Keying) D) RNRZ

2. In which transmission technique is the entire bandwidth of the communication channel used by a single data signal?

A) Broadband Transmission B) Multiplexing C) Baseband Transmission D) Modulation

3. What is the primary purpose of multiplexing in data communication?

A) To increase the speed of individual data streams B) To allow multiple data streams to share a single communication channel C) To convert analog signals to digital signals D) To detect and correct errors in transmission

4. Which type of transmission medium uses light pulses to transmit data?

A) Coaxial Cable B) Twisted Pair Cable C) Fiber Optic Cable D) Microwave

5. What is the main advantage of using TDM (Time Division Multiplexing)?

A) Efficient use of bandwidth for varying data rates B) Simpler hardware implementation compared to FDM C) Guarantees equal bandwidth for all users in each time slot D) Less susceptible to crosstalk

6. Which encoding technique uses a transition in the middle of each bit period to represent data, ensuring self-clocking?

A) NRZ-I (Non-Return to Zero Inverted) B) NRZ-L (Non-Return to Zero Level) C) Manchester Encoding D) Bipolar AMI

7. What does FDM (Frequency Division Multiplexing) divide the communication channel into?

A) Time slots B) Sub-channels with different frequencies C) Codes D) Physical links

8. Which error handling mechanism involves retransmitting the entire block of data if an error is detected?

A) Parity Check B) Checksum C) ARQ (Automatic Repeat reQuest) D) CRC (Cyclic Redundancy Check)

9. In broadband transmission, how is data transmitted?

A) As a single digital signal over the entire bandwidth B) As multiple analog signals, each occupying a different frequency band C) As digital signals modulated onto analog carriers D) As a series of pulses without modulation

10. What is the primary function of a modem?

A) To multiplex multiple signals B) To encode digital data for transmission C) To modulate and demodulate signals for analog transmission D) To detect and correct errors

11. Which of the following is a method of analog-to-analog modulation?

A) ASK B) FSK C) PSK D) AM (Amplitude Modulation)

12. What is the main difference between baseband and broadband transmission?

A) Baseband uses multiple channels, broadband uses one. B) Baseband transmits raw digital data, broadband transmits modulated analog signals. C) Baseband is limited to short distances, broadband to long. D) Baseband uses higher frequencies than broadband.

13. Which multiplexing technique combines multiple signals into a single high-speed data stream by assigning unique codes to each signal?

A) TDM B) FDM C) WDM D) CDM (Code Division Multiplexing)

14. Which transmission medium is most susceptible to electromagnetic interference (EMI)?

A) Fiber Optic Cable B) Coaxial Cable C) Shielded Twisted Pair (STP) D) Unshielded Twisted Pair (UTP)

15. What is the purpose of a parity bit in error detection?

A) To retransmit corrupted data B) To correct single-bit errors C) To indicate if the number of '1' bits is odd or even D) To provide a checksum for a block of data

16. Which modulation technique uses changes in the frequency of a carrier wave to represent digital data?

A) ASK B) PSK C) FSK (Frequency Shift Keying) D) QAM

17. What is a disadvantage of using Twisted Pair cable for high-speed data transmission over long distances?

A) High cost B) Susceptibility to crosstalk and EMI C) Low bandwidth capacity D) Requires complex modulation techniques

18. Which type of ARQ protocol uses a negative acknowledgment (NAK) to request retransmission?

A) Stop-and-Wait ARQ B) Go-Back-N ARQ C) Selective Repeat ARQ D) Sliding Window ARQ

19. What is the primary characteristic of NRZ-L encoding?

A) A voltage level transition occurs at the beginning of each bit period. B) A voltage level transition occurs in the middle of each bit period. C) A voltage level represents the bit value (e.g., high for 1, low for 0). D) A transition represents a 0 bit, no transition represents a 1 bit.

20. Which technique is used to transmit multiple digital signals over a single analog channel by assigning each signal a different carrier frequency?

A) TDM B) FDM C) WDM D) CDM

21. What is the main advantage of Fiber Optic cable over other transmission media?

A) Low cost and easy installation B) High bandwidth, low attenuation, and immunity to EMI C) Flexibility and ease of splicing D) Higher signal strength over short distances

22. Which error detection method calculates a sum of the data bytes and sends it along with the data?

A) Parity Check B) Checksum C) CRC D) LRC (Longitudinal Redundancy Check)

23. Which modulation scheme is used in DSL (Digital Subscriber Line) technology?

A) ASK B) FSK C) PSK D) QAM (Quadrature Amplitude Modulation)

24. What is the primary issue addressed by the 'Return to Zero' (RZ) encoding scheme?

A) Achieving higher data rates B) Ensuring synchronization by returning to zero voltage between bits C) Reducing power consumption D) Minimizing crosstalk

25. Which multiplexing method divides the channel into fixed-length time slots that are allocated to each user, regardless of whether they have data to send?

A) Statistical TDM (STDM) B) Synchronous TDM C) FDM D) WDM

26. What is the purpose of a CRC (Cyclic Redundancy Check) in error handling?

A) To provide a simple odd/even bit count B) To perform a simple addition of data segments C) To use polynomial division for detecting burst errors D) To request retransmission of corrupted frames

27. Which of the following is a digital-to-digital encoding technique?

A) ASK B) FSK C) Manchester Encoding D) AM

28. In broadband transmission, multiple signals can coexist on the same link because they are separated by:

A) Time slots B) Different spreading codes C) Different frequency bands D) Different voltage levels

29. What is the primary advantage of Statistical TDM (STDM) over Synchronous TDM?

A) Simpler implementation B) Guaranteed bandwidth for all users C) More efficient use of bandwidth by dynamically allocating time slots D) Higher maximum data rate

30. Which type of error handling mechanism provides the highest level of error detection capability for burst errors?

A) Parity Bit B) Checksum C) CRC D) VRC (Vertical Redundancy Check)

31. Which modulation technique uses changes in the phase of a carrier wave to represent digital data?

A) ASK B) FSK C) PSK (Phase Shift Keying) D) AM

32. Which of the following is NOT a type of multiplexing?

A) Time Division Multiplexing (TDM) B) Frequency Division Multiplexing (FDM) C) Amplitude Modulation (AM) D) Wavelength Division Multiplexing (WDM)

33. What is the main advantage of using Coaxial Cable compared to Twisted Pair?

A) Higher bandwidth and better noise immunity B) Lower cost and easier installation C) Greater flexibility D) Less susceptible to crosstalk

34. In ARQ protocols, what is the purpose of a positive acknowledgment (ACK)?

A) To indicate that an error has been detected and data needs retransmission B) To confirm successful reception of data C) To request the sender to stop transmitting D) To signal the end of the transmission

35. Which digital encoding technique uses a transition at the beginning of each bit period, and an additional transition in the middle only if the bit is a '1'?

A) NRZ-L B) NRZ-I C) Manchester Encoding D) Bipolar AMI

36. What is the primary characteristic of WDM (Wavelength Division Multiplexing)?

A) It multiplexes signals based on time slots. B) It multiplexes signals based on different frequencies. C) It multiplexes signals based on different wavelengths of light. D) It multiplexes signals based on unique codes.

37. Which of the following is a type of transmission medium that uses guided propagation?

A) Microwave B) Infrared C) Radio Waves D) Twisted Pair Cable

38. What is the main goal of 'error handling mechanisms' in data transmission?

A) To increase transmission speed B) To ensure the integrity and reliability of transmitted data C) To reduce the cost of transmission D) To allow more users to share the channel simultaneously

39. Which modulation technique combines changes in amplitude and phase to represent digital data?

A) FSK B) PSK C) QAM D) ASK

40. What is a key limitation of NRZ-L encoding?

A) It requires a return to zero voltage level between bits, reducing efficiency. B) It lacks sufficient transitions for clock recovery, especially with long strings of 0s or 1s. C) It is highly susceptible to noise. D) It requires complex decoding circuitry.

41. Which multiplexing technique is commonly used in fiber optic communication?

A) TDM B) FDM C) WDM D) CDM

42. What is the difference between an error detection code and an error correction code?

A) Detection codes are faster, while correction codes are more accurate. B) Detection codes only identify errors, while correction codes can also fix them. C) Detection codes use parity bits, while correction codes use checksums. D) Detection codes are used for analog signals, correction codes for digital.

43. Which of the following is an example of unguided transmission media?

A) Ethernet Cable B) Fiber Optic Cable C) Satellite Communication D) Telephone Line

44. What is the primary function of a 'demodulator' in a communication system?

A) To convert analog signals to digital signals B) To convert digital signals to analog signals C) To extract the original signal from a modulated carrier wave D) To combine multiple signals into one

45. Which data encoding scheme uses three voltage levels (+V, 0, -V) and alternates the polarity for '1' bits, with no transition for '0' bits?

A) NRZ-L B) NRZ-I C) Manchester Encoding D) Bipolar AMI (Alternate Mark Inversion)

46. What is the main benefit of using broadband transmission over baseband for long-distance communication?

A) Simpler signal processing B) Higher data rates over longer distances due to signal conditioning C) Lower equipment cost D) Direct transmission of digital signals without modulation

47. Which type of multiplexing is most suitable for transmitting multiple television channels over a single coaxial cable?

A) TDM B) FDM C) WDM D) CDM

48. In the context of ARQ, what does 'Selective Repeat' aim to improve over 'Go-Back-N'?

A) Simplicity of implementation B) Efficiency by only retransmitting the specific corrupted frames C) Maximum number of simultaneous users D) Speed of initial connection establishment

49. Which encoding technique inherently provides clock synchronization without requiring a separate clock signal?

A) NRZ-L B) NRZ-I C) Bipolar AMI D) Manchester Encoding

Transmission Techniques - data encoding, modulation, broadband and baseband transmission, multiplexing, transmission media, error handling mechanisms - Online Test

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