Total marks: 60 · Duration: 1 hour 30 minutes
Instructions to candidates
• Answer all questions. • Use black ink or black ball-point pen. • The number of marks is given in brackets [ ] at the end of each question or part question. • Show your working in any conversions or calculations. • The total number of marks for this paper is 60. • All the information you need is contained within the questions.
Paper
Section A — Structured Questions (44 marks)
1. Data representation
(a) Convert the 8-bit binary number 0110 1010 into denary. [2]
(b) Convert the denary number 75 into an 8-bit binary number. [2]
(c) Add the two binary numbers 0101 1001 and 0010 0110. Show your answer as an 8-bit binary number. [3]
(d) State one reason why computers store and process data in binary. [1]
(e) Convert the binary number 1101 1110 into hexadecimal. [2]
2. Hardware
(a) State the main role of the CPU in a computer system. [2]
(b) Explain two differences between RAM and ROM. [4]
(c) Explain the purpose of cache memory and why it improves the performance of a computer. [3]
3. Networks
(a) State one difference between a LAN and a WAN. [2]
(b) Describe the star network topology, and state one advantage of it. [3]
(c) Explain the role of a router in a network, and explain why network protocols are needed. [4]
4. Algorithms and logic
(a) Complete the truth table below for a two-input AND gate.
| Input A | Input B | Output |
|---|---|---|
| 0 | 0 | ? |
| 0 | 1 | ? |
| 1 | 0 | ? |
| 1 | 1 | ? |
(b) Explain the difference between a linear search and a binary search, and state one condition that must be met before a binary search can be used. [5]
5. Security and ethics
(a) State what is meant by malware, and give one example of a type of malware. [2]
(b) Explain two methods a business could use to protect its computer systems from unauthorised access. [4]
(c) Explain one ethical or legal issue raised by organisations collecting large amounts of personal data. [2]
Section B — Extended Response (16 marks)
6. (a) Describe the fetch–decode–execute cycle carried out by the CPU. [6]
(b) Explain two factors that affect the performance (speed) of a CPU. [4]
7. Discuss the environmental and ethical impacts of the widespread use of digital technology, referring to both benefits and drawbacks. [6]