1. Which of the following is used to detect errors in a transmitted message?
- A) Parity Bit
- B) Error-correcting code
- C) Checksum
- D) All of the above
Answer: D) All of the above
2. What is the main purpose of a parity bit?
- A) To correct errors in the received message
- B) To detect errors in the received message
- C) To increase the transmission speed
- D) To reduce the size of the message
Answer: B) To detect errors in the received message
3. In the case of a single bit error, which error detection technique is most effective?
- A) Checksum
- B) Cyclic Redundancy Check (CRC)
- C) Parity Bit
- D) Hamming Code
Answer: C) Parity Bit
4. Which of the following error correction methods is based on the use of redundant data?
- A) Hamming Code
- B) Checksum
- C) Parity Bit
- D) Cyclic Redundancy Check (CRC)
Answer: A) Hamming Code
5. Which technique is used to detect errors in large blocks of data by dividing data into smaller blocks and generating a checksum for each block?
- A) Hamming Code
- B) Block Check Character (BCC)
- C) Parity Bit
- D) Cyclic Redundancy Check (CRC)
Answer: B) Block Check Character (BCC)
6. What is the main advantage of the Cyclic Redundancy Check (CRC) over other error detection techniques?
- A) It can detect more complex errors
- B) It uses fewer resources
- C) It requires less redundant data
- D) It does not require sender and receiver to agree on a key
Answer: A) It can detect more complex errors
7. Which error detection method is most commonly used in Ethernet and other networking technologies?
- A) Parity Bit
- B) Hamming Code
- C) Checksum
- D) Cyclic Redundancy Check (CRC)
Answer: D) Cyclic Redundancy Check (CRC)
8. Which error correction code can detect and correct single-bit errors and detect two-bit errors?
- A) Hamming Code
- B) CRC
- C) Reed-Solomon Code
- D) Block Check Character (BCC)
Answer: A) Hamming Code
9. In which error detection method is a redundant check value added to the data to ensure the total sum is divisible by a specific value (usually 256)?
- A) Parity Bit
- B) Checksum
- C) Hamming Code
- D) Cyclic Redundancy Check (CRC)
Answer: B) Checksum
10. Which of the following is a method to correct errors in the transmitted data using a series of parity bits?
- A) Hamming Code
- B) Parity Bit
- C) Checksum
- D) Cyclic Redundancy Check (CRC)
Answer: A) Hamming Code
11. What type of errors can be detected by a two-dimensional parity check?
- A) Single-bit errors
- B) Double-bit errors
- C) Burst errors
- D) All of the above
Answer: D) All of the above
12. In a Hamming (7,4) code, how many parity bits are used for a 4-bit data word?
- A) 3
- B) 4
- C) 5
- D) 2
Answer: A) 3
13. Which of the following statements is true about the Checksum method?
- A) It detects errors based on a redundant bit added to the data
- B) It can correct errors but cannot detect them
- C) It uses a mathematical sum of the data to check for transmission errors
- D) It is more complex than CRC
Answer: C) It uses a mathematical sum of the data to check for transmission errors
14. Which of the following is a property of the Hamming Code?
- A) It can detect and correct two-bit errors
- B) It uses only one parity bit
- C) It requires a minimum of three bits for error correction
- D) It uses multiple redundant bits for error detection and correction
Answer: D) It uses multiple redundant bits for error detection and correction
15. In the Cyclic Redundancy Check (CRC), the divisor used for division is typically represented by what kind of polynomial?
- A) Binary Polynomial
- B) Decimal Polynomial
- C) Hexadecimal Polynomial
- D) Octal Polynomial
Answer: A) Binary Polynomial
16. Which of the following is the main limitation of the parity bit as an error detection method?
- A) It cannot detect even numbers of bit errors
- B) It requires additional transmission bandwidth
- C) It cannot correct any errors
- D) It is not compatible with digital systems
Answer: A) It cannot detect even numbers of bit errors
17. Which type of error does the Hamming Code detect?
- A) Single-bit errors
- B) Two-bit errors
- C) Burst errors
- D) It cannot detect errors
Answer: A) Single-bit errors
18. What is the primary function of error correction codes in digital communication systems?
- A) To reduce the size of the transmitted data
- B) To ensure that the data is transmitted faster
- C) To detect and correct errors in the transmitted data
- D) To increase the security of the transmitted data
Answer: C) To detect and correct errors in the transmitted data
19. Which of the following error detection/correction methods is most commonly used in CDs, DVDs, and QR codes?
- A) Hamming Code
- B) Cyclic Redundancy Check (CRC)
- C) Reed-Solomon Code
- D) Parity Bit
Answer: C) Reed-Solomon Code
20. Which of the following is a key feature of the error detection technique known as ‘checksum’?
- A) It divides the data into smaller blocks
- B) It uses a polynomial division method
- C) It detects errors by calculating the sum of the data
- D) It uses multiple parity bits
Answer: C) It detects errors by calculating the sum of the data