Convert 0x7F and −1 into 8-bit binary (two's complement for −1) and explain why 0x7F is the largest positive 8-bit two's complement value.
From Paper 1: Principles of computer science
2(b)3 marks
Add the 8-bit two's complement numbers 01100100 and 00110010 and explain the result.
From Paper 1: Principles of computer science
2(c)4 marks
Explain the difference between an array, a record and a list in Python, giving a use of each.
From Paper 1: Principles of computer science
2(d)3 marks
An image of 800 × 600 pixels uses 256 colours. Calculate its size in kibibytes (KiB).
From Paper 2: Application of computational thinking (practice version)
78 marks
Implement a stack class in Python with push, pop and peek methods and an isEmpty method. pop and peek must handle an empty stack sensibly. Use it to check whether the brackets in a string such as '(a[b]{c})' are balanced.
Score 0 / 21 · 0 of 5 marked
This paper is written by Plasmo in the style of the Edexcel A-Level Computer Science exam. It is not a past paper and is not produced or endorsed by the exam board.
Data Exam Questions: Edexcel A-Level Computer Science | Plasmo