CXC CAPE Information Technology Unit 1 — Paper 02 (Structured and Essay)

Total marks: 90 · Duration: 2 hours 30 minutes

Instructions to candidates

• This paper consists of SIX questions arranged in THREE sections, corresponding to the three Modules of Unit 1.
• Answer ALL SIX questions. Each question is worth 15 marks. Marks for each part are shown in brackets.
• Begin each answer on a new page and write the question number clearly in the margin.
• Where a question asks for a diagram, chart, table or trace, you must draw it in your answer booklet, fully labelled. No diagrams or figures are supplied with this paper — all data you need is given in tables or in the text of the question.
• Where calculations or algorithm traces are required, show all working. Marks are available for method even where the final answer is incorrect.
• Pseudocode may be written in any consistent style, provided that sequence, selection, iteration and input/output are unambiguous.
• Silent, non-programmable calculators are permitted.
• Unit 1 covers Module 1 (Fundamentals of Information Technology), Module 2 (Information Technology Systems) and Module 3 (Information and Problem-Solving).

Paper

Section A — Module 1: Fundamentals of Information Technology (answer BOTH) — 30 marks

1. (a) Distinguish between data and information, and state THREE characteristics that determine the quality of information. (6 marks)

(b) Convert each of the following, showing your method. (5 marks)

(c) Using two's complement in 8 bits, calculate 45 − 62. Show the representation of each operand and state the denary value of your result. (4 marks)

2. (a) Describe the role of each of the following in the fetch–execute cycle: the program counter, the memory address register, the memory data register, the instruction register, and the arithmetic logic unit. (5 marks)

(b) A school is choosing between a solid-state drive and a magnetic hard disk drive for its student record server. Compare the two with reference to access time, durability, capacity per unit cost and power consumption, and make a recommendation. (6 marks)

(c) Explain the difference between cache memory, main memory and virtual memory, and explain why a system with insufficient main memory may exhibit disk thrashing. (4 marks)

Section B — Module 2: Information Technology Systems (answer BOTH) — 30 marks

3. (a) Describe the star, bus and mesh network topologies. For each, state one advantage and one disadvantage. Using a labelled sketch of a star topology, indicate the central device and three nodes. (8 marks)

(b) A retail chain has 40 branches. Explain THREE benefits and TWO risks of moving its point-of-sale system from standalone terminals in each branch to a centralised cloud-hosted system. (7 marks)

4. A regional clinic stores patient records in a relational database. The following table is an extract from a single unnormalised table, APPOINTMENT.

(a) Identify ONE insertion anomaly, ONE update anomaly and ONE deletion anomaly that this design permits. (6 marks)

(b) Redesign the data into third normal form. For each resulting relation, list the attributes and underline or clearly state the primary key, and identify any foreign keys. (6 marks)

(c) Explain what is meant by referential integrity, and state one consequence of its absence in this database. (3 marks)

Section C — Module 3: Information and Problem-Solving (answer BOTH) — 30 marks

5. (a) State the stages of the problem-solving process as applied to computing, from problem definition to maintenance. (5 marks)

(b) A shop applies a discount to a customer's total bill according to the table below.

A further 2% is deducted from the discounted amount if the customer is a loyalty-card holder.

Write an algorithm in pseudocode that reads the total bill and a loyalty flag, calculates and outputs the amount payable. (7 marks)

(c) Trace your algorithm for a bill of $2 500 held by a loyalty-card holder, showing the value of each variable at each stage in a table. (3 marks)

6. (a) Distinguish between iteration and recursion, and state one advantage of each. (4 marks)

(b) Study the following pseudocode.

READ n
total ← 0
count ← 1
WHILE count <= n DO
    IF count MOD 3 = 0 OR count MOD 5 = 0 THEN
        total ← total + count
    ENDIF
    count ← count + 1
ENDWHILE
PRINT total

State the output when n = 10, and describe in one sentence what the algorithm computes. (4 marks)

(c) An array MARKS holds the scores of 200 students. Write an algorithm that outputs the highest mark, the lowest mark and the mean mark, using a single pass through the array. (7 marks)