Methods of Error Detection (Cambridge (CIE) O Level Computer Science): Exam Questions

Four 7-bit binary values are transmitted from one computer to another. A parity bit is added to each binary value creating 8-bit binary values. All the binary values are transmitted and received correctly.

Identify whether each 8-bit binary value has been sent using odd or even parity by writing odd or even in the type of parity column.

The contents of three binary registers have been transmitted from one computer to another.

Even parity has been used as an error detection method.

The outcome after transmission is:

No errors have been detected in Register A and Register C.

An error has been detected in Register B.

Complete the parity bit for each register to show the given outcome

Victoria is entering data into a computer system. The data will be transmitted to cloud storage.

A check digit is used to check whether data is correct when entered into the system.

Describe how a check digit can be used to make sure the data entered is correct.

Why is it important for computers to check that data is in the expected format?

Provide one example of a format where errors could occur.

Data will be checked using a checksum.

Describe how a checksum can be used to check that data entered into a system has been transmitted correctly

Explain how the Automatic Repeat reQuest (ARQ) protocol ensures data integrity during transmission