WAEC Computer Science 2024
Questions & Answers

The CPU, often called the brain of the computer, fetches, decodes, and executes instructions from programs, performing arithmetic, logical, control, and input/output operations essential for system functionality.

An operating system manages hardware and software resources, providing services for programs; Windows 10 is a full OS, while others are applications for word processing, image editing, and web browsing.

Data processing involves collecting, manipulating, and analyzing raw data using algorithms to produce usable information, such as sorting, calculating, or summarizing for decision-making.

Input devices allow users to enter data into the computer; a scanner captures images or text from physical documents, converting them to digital format, unlike output devices like printers or monitors.

To convert decimal 7 to binary: 7 ÷ 2 = 3 remainder 1; 3 ÷ 2 = 1 remainder 1; 1 ÷ 2 = 0 remainder 1; reading remainders bottom-up gives 111, representing 4 + 2 + 1.

RAM is volatile memory, meaning it loses all stored data when power is turned off; it provides temporary, fast access for running programs, contrasting with non-volatile storage like ROM or hard drives.

A bit is the smallest unit of digital information, representing a binary digit (0 or 1), forming the basis for all data storage and processing in computers.

Secondary storage provides non-volatile, long-term data retention like HDDs, which use magnetic disks to store large amounts of data; primary storage like RAM and registers is temporary and volatile.

Antivirus software detects, prevents, and removes malicious software (malware) like viruses, trojans, and ransomware, safeguarding system integrity, data, and privacy.

JavaScript is a versatile scripting language primarily used for client-side web development to add interactivity; HTML (original option) is a markup language, not programming, so replaced for accuracy; others are for business, scientific, or educational purposes.

Debugging involves identifying, analyzing, and fixing bugs (errors) in code through testing, tracing, and tools like debuggers, ensuring the program runs correctly.

GUIs use visual elements like icons, windows, menus, and pointers for intuitive user interaction, simplifying operations compared to command-line interfaces.

A URL (Uniform Resource Locator) is a standardized address for locating resources on the internet, specifying protocol, domain, and path; original option 'Universal' was incorrect and replaced.

In a star topology, devices connect to a central hub or switch, allowing efficient data flow and easy fault isolation, though hub failure affects the entire network.

A firewall monitors and controls incoming/outgoing network traffic based on security rules, preventing unauthorized access and protecting against threats like hackers.

Application software performs user-specific tasks like data analysis in Microsoft Excel; others are system-level (BIOS, drivers) or core OS components.

Cookies are small text files stored by browsers to track user preferences, sessions, and behavior, enhancing personalized web experiences but raising privacy concerns.

.txt is the standard extension for plain text files readable by any text editor; others denote image (.jpg), executable (.exe), or audio (.mp3) files.

The Control Unit coordinates CPU operations by fetching instructions from memory, decoding them, and signaling other components like ALU for execution.

Cloud computing enables anytime, anywhere access to data and applications via the internet, promoting scalability, collaboration, and reduced local hardware needs.

A DBMS like MySQL organizes, stores, retrieves, and secures data in databases, ensuring integrity, concurrency, and efficient querying for applications.

System software supports computer hardware operation; utility software (e.g., disk cleanup) maintains system performance, unlike user applications like browsers or editors.

Uploading transfers files from a local device to a remote server (e.g., cloud storage), opposite of downloading, which retrieves data from the server.

Serial ports transmit data sequentially, one bit at a time over a single channel (e.g., RS-232), suitable for low-speed peripherals like modems, contrasting parallel ports.

Routers connect multiple networks (e.g., LAN to WAN) and forward data packets using IP addresses, enabling internet access and traffic management.

A syntax error occurs when code violates language rules (e.g., missing semicolon), preventing compilation; others are hardware or external issues.

Bandwidth measures the maximum data transfer rate (e.g., in Mbps) over a network link, determining capacity for activities like streaming or downloading.

Open-source software provides publicly available source code, allowing free use, modification, and distribution, fostering community collaboration (e.g., Linux).

Backups create copies of data for restoration after loss from failures, deletions, or disasters, following the 3-2-1 rule (3 copies, 2 media, 1 offsite).

A Trojan disguises as legitimate software to trick users into installing malware, enabling unauthorized access; others are security tools or hardware.

Output devices present processed data to users in readable form, such as monitors (visual) or printers (physical), completing the input-process-output cycle.

Standard email format is local-part@domain (e.g., user@example.com); option A represents the core structure, while B is a domain example without @.

Spreadsheets like Excel excel in numerical data manipulation, formulas, charts, and what-if analysis for tasks like budgeting or statistical modeling.

The motherboard's CPU socket securely mounts the processor, providing electrical connections; others are external peripherals or ports.

Encryption scrambles data using algorithms and keys, making it unreadable without decryption, ensuring confidentiality during storage or transmission.

Mainframes process massive transaction volumes for enterprises (e.g., banking), supporting thousands of users with high reliability and scalability.

A compiler converts high-level source code (e.g., C++) into machine-readable binary code in one go, optimizing for execution speed.

Wi-Fi enables wireless data transmission over radio waves using IEEE 802.11 standards, allowing device connectivity without physical cables.

Cache memory, small and fast (e.g., L1/L2 in CPU), stores frequently accessed data/instructions to reduce latency compared to slower main memory.

Peer-to-peer networks lack a central server for management, leading to difficulties in security enforcement, backups, and scalability as devices share equal roles.