Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:Communication systems often add redundancy to detect data corruption introduced by noise or interference. The simplest redundancy mechanism is a single parity bit appended to each data word. This question verifies that you understand parity as a detection mechanism, not a correction mechanism, and that it is sensitive primarily to odd numbers of bit errors.
Given Data / Assumptions:
Concept / Approach:At the receiver, the system recomputes parity on the received data and compares it with the received parity bit. A mismatch indicates that an odd number of bits flipped (most commonly a single-bit error). Parity cannot localize the error nor correct it; it merely signals that corruption likely occurred.
Step-by-Step Solution:
Choose parity type (odd/even) and compute the parity bit before transmission.Transmit data + parity.On reception, recompute parity and compare to the received parity bit.If mismatch, flag an error and request retransmission or discard, depending on protocol.Verification / Alternative check:Consider a single flipped bit: parity changes and a mismatch is detected. Consider two flipped bits: parity may match (missed detection), demonstrating the limitation of single-bit parity.
Why Other Options Are Wrong:
Incorrect: Parity is precisely an error-detection method.Two-bit only / correction claim: Parity detects odd-number-of-bit errors and does not correct.Common Pitfalls:Overestimating parity’s capability; for stronger protection use checksums or CRCs which detect more error patterns.
Final Answer:Correct
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