OCR GCSE
Computer Science [J277]

Define the term 'data packet'.

Outline how protocols enable successful network communication.

With respect to online banking on public Wi-Fi, outline one security risk.

Describe two critical devices required for a public wireless network to function.

A die is rolled N times and the results stored in a collection called ROLLS. The die has normal faces, that is, showing numbers from 1 to 6 inclusive across its sides. The die is considered biased if both the number of rolls (N) is greater than 1000 and the average value across all N rolls is either greater than 3.5 + 100/N or less than 3.5 - 100/N. If there are 1000 rolls or less then it is not known with sufficient confidence if the die is biased or not. Based on this approach, construct an algorithm to determine whether or not the die is biased. Output the verdict.

NOR

XOR

XNOR

NAND

Explain how binary search may be more efficient than linear search at finding a target value in array data.

Given a 2D array called ARR of size 4x3 and an empty 1D array called BIGGEST of size 4, construct an algorithm to sequentially fill BIGGEST with the biggest number in each ARR row such that the index of each number in BIGGEST is the same as its original ARR row index. The more positive or less negative a number, the bigger it is - for example, 7, 0 and -2 are all considered bigger than -10. ARR may contain one or more negative numbers. For example, consider the following 2D array: