WAEC Computer Studies 2024 Theory Past Questions

Model answer

(a)(i) Sign in: to enter a username, password or other authentication details to access a website, application or online service, allowing the user to access their account and personalized content/features. (ii) Search engine: a website or program that enables people to find information online by searching for keywords or phrases, e.g. Google, Bing, Yahoo. (b)(i) I. Figure 1: Random access method. II. Figure 2: Sequential access method. (ii) Figure 1 -- Advantage: records can be accessed directly regardless of physical location, ideal for fast data retrieval. Disadvantage: a complex indexing system is required to manage record locations. Figure 2 -- Advantage: straightforward to implement, records stored/accessed linearly, less prone to data corruption, efficient for large files. Disadvantage: slower data retrieval, especially if the desired record is located far into the sequence.

Model answer

(a)(i) A data cable is a type of cable used to transmit data between devices such as computers, servers and peripherals. (ii) Coaxial cables; Fibre optic cables; Twisted pair cable. (iii) A higher bus speed allows for faster data transfer between the processor and RAM, lower latency and higher throughput, allowing more data to be transmitted simultaneously and at faster speed. (b)(i) Register: a high-speed temporary storage device built into a computer's processor that temporarily holds data being processed or converted. (ii) Address: a unique location or identifier where data is stored or retrieved; addresses serve as pointers to access and manipulate data during conversion.

Model answer

(a)(i) File: a collection of related data (records) stored together on a computer. (ii) Record: a single entry or row in a file, containing a set of related data; the collection of fields that describes a specific entity. (iii) Field: a single piece of data within a record representing a specific attribute or characteristic; a column in a spreadsheet. (b)(i) Other fields: Student ID; Date of birth; Gender; Email; Phone number; Parent/Guardian name; Class. (ii) Steps: search for the student's record using a unique identifier such as the student ID; identify the specific field to be edited and select it; make adjustments and save changes made to the record. (iii) MS Access; MySQL / Oracle / MongoDB (any two database applications).

Model answer

(a)(i) A logic truth table is a mathematical table used to evaluate the truth value of logical statements or arguments; it displays logical operations on input signals in table format. (ii) Types of logic gate: OR gate, AND gate (also acceptable: NOT, NOR, NAND, XOR, EXNOR gates). (iii) Truth table -- X=0,Y=0: Z(OR)=0, Z(AND)=0. X=0,Y=1: Z(OR)=1, Z(AND)=0. X=1,Y=0: Z(OR)=1, Z(AND)=0. X=1,Y=1: Z(OR)=1, Z(AND)=1. (b) A comparator is a logic device that compares two input values (X and Y) and produces an output based on their relative values -- a digital circuit that determines whether one value is greater than, less than or equal to another. The output is 1 if the condition is met and 0 if not. Comparators are commonly used in digital systems for data comparison, error detection, sorting and searching, digital arithmetic circuits, etc.

Model answer

(a) Compiler vs Interpreter: A compiler generates intermediate object code and takes the entire program at once, is comparatively faster in execution, has more difficult error detection, and requires more memory. An interpreter generates no intermediate object code, translates the source program line by line, is slower in execution, has comparatively easier error detection, and requires less memory. (b)(i) High level language: provides a higher level of abstraction, allowing programmers to focus on logic and functionality rather than hardware/complex low-level operations; easy to code, debug and maintain. (ii) Low level language: faster execution times; greater control over hardware resources. (c) Characteristics of a good program: Correctness -- produces the desired output for a given input. Maintainability -- easy to modify, update and debug. (Other acceptable: readability, reliability, efficiency, portability.)