TestOut LabSim A+ Certification Practice Exam

Which of the following is an error detection technique that can detect errors with only one bit?

1. Checksum

2. Redundancy check

3. Parity

4. CRC (Cyclic Redundancy Check)

The correct answer is: Parity

Parity is an error detection technique that can identify errors with a single bit. It works by adding an additional bit, known as a parity bit, to a string of binary data. This bit is set to either 0 or 1, depending on whether the total number of 1s in the data is even or odd. For even parity, the parity bit is set to 1 if the count of 1s is odd, making the total count even. Conversely, for odd parity, the bit is set to 1 if the count of 1s is even, yielding an odd total. When the data is transmitted, the receiver can count the number of 1s and check it against the expected parity. If the count does not match the expected parity, it indicates that an error has occurred in the transmission. However, this technique only detects single-bit errors, as it cannot identify multiple-bit errors where the parity may still appear correct. Other options like checksum, redundancy check, and CRC provide more advanced error detection capabilities, often capable of detecting multiple-bit errors or, in the case of CRC, providing error correction capabilities as well. However, they do not focus solely on the detection of single-bit errors as effectively as parity does