Q#1: Error detection is used to:
(A) Identify errors in transmitted data
(B) Correct errors automatically
(C) Amplify signals
(D) None
Answer: (A) Identify errors in transmitted data
Q#2: Error correction is used to:
(A) Correct detected errors at receiver
(B) Detect errors only
(C) Encode data
(D) Modulate signals
Answer: (A) Correct detected errors at receiver
Q#3: Noise in transmission can cause:
(A) Bit errors
(B) Signal attenuation
(C) Crosstalk
(D) All of the above
Answer: (D) All of the above
Q#4: Single-bit error affects:
(A) Only one bit in a data unit
(B) Entire frame
(C) Multiple frames
(D) None
Answer: (A) Only one bit in a data unit
Q#5: Burst error affects:
(A) Two or more consecutive bits
(B) Only one bit
(C) Random bits
(D) None
Answer: (A) Two or more consecutive bits
Q#6: Parity check adds:
(A) One extra bit to make total 1s even or odd
(B) Two bits
(C) Error-correcting code
(D) None
Answer: (A) One extra bit to make total 1s even or odd
Q#7: Even parity ensures:
(A) Total number of 1s is even
(B) Total number of 1s is odd
(C) Data is encrypted
(D) None
Answer: (A) Total number of 1s is even
Q#8: Odd parity ensures:
(A) Total number of 1s is odd
(B) Total number of 1s is even
(C) Checks burst errors
(D) None
Answer: (A) Total number of 1s is odd
Q#9: Checksum is:
(A) Sum of data units for error detection
(B) Error correction code
(C) Modulation technique
(D) Multiplexing method
Answer: (A) Sum of data units for error detection
Q#10: Two-dimensional parity can detect:
(A) Single-bit and some burst errors
(B) All burst errors
(C) Only even parity
(D) None
Answer: (A) Single-bit and some burst errors
Q#11: Cyclic Redundancy Check (CRC) is:
(A) Polynomial-based error detection
(B) Parity bit
(C) Checksum
(D) None
Answer: (A) Polynomial-based error detection
Q#12: Hamming code is used for:
(A) Error detection and single-bit correction
(B) Only detection
(C) Modulation
(D) None
Answer: (A) Error detection and single-bit correction
Q#13: Redundant bits in Hamming code are used for:
(A) Locating error position
(B) Data compression
(C) Multiplexing
(D) None
Answer: (A) Locating error position
Q#14: ARQ (Automatic Repeat Request) is:
(A) Error correction by retransmission
(B) Forward error correction
(C) Parity check
(D) None
Answer: (A) Error correction by retransmission
Q#15: Stop-and-wait ARQ waits:
(A) For acknowledgment before sending next frame
(B) Sends all frames at once
(C) Uses parity
(D) None
Answer: (A) For acknowledgment before sending next frame
Q#16: Go-Back-N ARQ retransmits:
(A) All frames from error onward
(B) Only erroneous frame
(C) All frames
(D) None
Answer: (A) All frames from error onward
Q#17: Selective Repeat ARQ retransmits:
(A) Only erroneous frames
(B) All frames
(C) None
(D) Parity bits only
Answer: (A) Only erroneous frames
Q#18: Forward Error Correction (FEC) adds:
(A) Redundant bits for receiver to correct errors
(B) Parity only
(C) No extra bits
(D) None
Answer: (A) Redundant bits for receiver to correct errors
Q#19: Parity bit cannot detect:
(A) Two-bit errors if both change
(B) Single-bit errors
(C) Odd number of errors
(D) None
Answer: (A) Two-bit errors if both change
Q#20: Error detection codes include:
(A) Parity
(B) Checksum
(C) CRC
(D) All of the above
Answer: (D) All of the above
Q#21: Error correction codes include:
(A) Hamming code
(B) Reed-Solomon
(C) Convolutional code
(D) All of the above
Answer: (D) All of the above
Q#22: Block codes work on:
(A) Fixed-size blocks of data
(B) Single bits only
(C) Variable length
(D) None
Answer: (A) Fixed-size blocks of data
Q#23: Convolutional codes work on:
(A) Continuous stream of bits
(B) Fixed blocks
(C) Parity only
(D) None
Answer: (A) Continuous stream of bits
Q#24: CRC polynomial is used to:
(A) Generate check value
(B) Detect errors
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#25: Error detection efficiency improves with:
(A) Longer check bits
(B) Shorter check bits
(C) Same as data bits
(D) None
Answer: (A) Longer check bits
Q#26: Reed-Solomon code is effective for:
(A) Burst errors
(B) Single-bit errors only
(C) Parity errors
(D) None
Answer: (A) Burst errors
Q#27: Parity bit position in Hamming code is:
(A) Powers of 2
(B) Consecutive positions
(C) End of frame
(D) Random
Answer: (A) Powers of 2
Q#28: Error detection and correction reduce:
(A) Retransmissions
(B) Bandwidth wastage
(C) Delay
(D) All of the above
Answer: (A) Retransmissions
(Note: Error detection/correction reduces retransmissions, which in turn reduces delay and bandwidth wastage, but the direct effect is reducing retransmissions.)
Q#29: Block check character (BCC) is:
(A) Additional bits for error detection in a block
(B) Modulation technique
(C) Multiplexing method
(D) None
Answer: (A) Additional bits for error detection in a block
Q#30: Even parity cannot detect:
(A) Two-bit errors in same block
(B) Single-bit errors
(C) Odd number of errors
(D) None
Answer: (A) Two-bit errors in same block
Q#31: Checksum detects errors by:
(A) Comparing sum at sender and receiver
(B) Parity comparison
(C) Bit inversion
(D) None
Answer: (A) Comparing sum at sender and receiver
Q#32: Hamming distance:
(A) Number of bits that differ between two code words
(B) Number of errors
(C) Transmission speed
(D) None
Answer: (A) Number of bits that differ between two code words
Q#33: Minimum Hamming distance determines:
(A) Error detection and correction capability
(B) Bandwidth
(C) Delay
(D) None
Answer: (A) Error detection and correction capability
Q#34: Single-bit error correction requires:
(A) Minimum Hamming distance of 3
(B) Minimum distance 2
(C) Parity only
(D) None
Answer: (A) Minimum Hamming distance of 3
Q#35: Two-bit error detection requires:
(A) Minimum Hamming distance of 3
(B) Distance 2
(C) Distance 1
(D) None
Answer: (A) Minimum Hamming distance of 3
Q#36: Redundant bits increase:
(A) Reliability
(B) Bandwidth usage
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#37: Parity check code type:
(A) Single-bit error detection
(B) Multiple-bit correction
(C) Burst error correction
(D) None
Answer: (A) Single-bit error detection
Q#38: FEC is used in:
(A) Satellite communication
(B) Wireless networks
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#39: ARQ used in:
(A) Data networks
(B) Satellite links
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#40: Two-dimensional parity arranges data in:
(A) Rows and columns
(B) Single line
(C) Random blocks
(D) None
Answer: (A) Rows and columns
Q#41: CRC advantage:
(A) High error detection capability
(B) Easy implementation in hardware
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#42: Burst error is common in:
(A) Wireless and storage media
(B) Twisted pair
(C) Fiber optics only
(D) None
Answer: (A) Wireless and storage media
Q#43: Parity check detects:
(A) Odd number of bit errors
(B) Even number
(C) Burst errors always
(D) None
Answer: (A) Odd number of bit errors
Q#44: Checksum can detect:
(A) All single-bit errors
(B) Some burst errors
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#45: Hamming code corrects:
(A) Single-bit errors
(B) Burst errors
(C) Two-bit errors
(D) None
Answer: (A) Single-bit errors
Q#46: ARQ efficiency decreases with:
(A) High error rate
(B) Low error rate
(C) Short distance
(D) None
Answer: (A) High error rate
Q#47: FEC efficiency improves with:
(A) Low error rate
(B) High error rate
(C) Noisy channel
(D) None
Answer: (B) High error rate
(Note: FEC is most beneficial in high error rate environments where retransmissions would be too costly.)
Q#48: Error detection without correction requires:
(A) Retransmission
(B) Redundant bits only
(C) None
(D) Both A and B
Answer: (D) Both A and B
Q#49: Parity bits in Hamming code are:
(A) Powers of 2 positions
(B) Random positions
(C) End positions
(D) None
Answer: (A) Powers of 2 positions
Q#50: Primary goal of error control:
(A) Reliable data transmission
(B) Reduce bandwidth
(C) Reduce delay only
(D) None
Answer: (A) Reliable data transmission