JAMB Computer Studies 2013
Questions & Answers

A student might mistakenly choose to perform arithmetic calculations or store program data by confusing the control unit with the ALU or memory components. The control unit functions by directing processor operations, fetching and decoding instructions, and coordinating the overall workflow among other hardware parts rather than executing math or holding data files directly. Common mistake: Confusing the supervisory coordination role of the control unit with the computational duties of the ALU.

One might select a queue or a linked list due to their common usage in general software applications. Recursion intrinsically depends on a stack because of its Last In, First Out (LIFO) architecture, which elegantly handles nested function calls by preserving return addresses and local variables in proper sequence. Common mistake: Mixing up the LIFO stack behavior required for function return tracking with the FIFO nature of queues.

Learners might choose real-time memory or random operating memory thinking they describe computer speed or volatile handling. ROM stands for Read-Only Memory, which designates non-volatile storage designed to hold permanent system instructions like basic firmware that must persist without power. Common mistake: Confusing the non-volatile permanent nature of ROM with volatile or real-time processing concepts.

An unobservant student might pick Pascal, Fortran, or COBOL because they are historically significant programming languages. JavaScript is the correct modern choice because it natively runs inside web browsers to deliver dynamic and interactive user experiences across modern websites. Common mistake: Selecting legacy programming languages that are no longer standard for web browser development.

Students might pick 1B, 1C, or 1D through simple arithmetic errors during the conversion process. Converting binary 11010 yields a decimal value of 26, which breaks down into one group of 16 and a remainder of 10, translating directly in hexadecimal as 1A where A represents 10. Common mistake: Making a calculation error in the final hexadecimal digit representation for decimal 26.

One might select MongoDB, Cassandra, or Redis by confusing relational database systems with NoSQL or key-value storage models. MySQL is a classic relational database management system that organizes information into structured tables linked by relationships and queried using SQL. Common mistake: Grouping modern NoSQL database systems together with traditional relational table-based systems.

Distractor check: A student might lean toward A or D thinking terms like 'Hyperlink' or 'Hosted' fit web technology, but these are distractor names. Reasoning to the answer: HTML stands for HyperText Markup Language, which uses tags to structure web content rather than acting as a hyperlink manager, high-level module, or hosted language. Common mistake: Confusing standard web document tags with generic software descriptors.

Distractor check: Options like A and C (Breadth-First Search and Depth-First Search) are familiar graph traversal techniques, making them tempting if you confuse traversal with shortest path calculation, while D (Kruskal’s) is associated with spanning trees. Reasoning to the answer: Dijkstra’s Algorithm computes the shortest path in a weighted graph from a source to all vertices. BFS and DFS work on unweighted graphs, and Kruskal’s finds minimum spanning trees. Common mistake: Mixing up algorithms that traverse graphs with those calculating weighted distances.

Distractor check: A student might guess A or D (O(n) or O(log n)) because they represent fast complexities, but these do not match quicksort's behavior. Reasoning to the answer: Quicksort’s average-case complexity is O(n log n) due to its divide-and-conquer partitioning. Worst-case is O(n^2), but O(n) and O(log n) don’t apply. Common mistake: Forgetting that partitioning overhead leads to O(n log n) on average.

Distractor check: A, C, and D (Monitor, Printer, and Speaker) are standard hardware units you can see, which might lead someone to think of them broadly as system components. Reasoning to the answer: A mouse sends user input to the computer, making it an input device. Monitors, printers, and speakers are output devices, displaying or producing data. Common mistake: Confusing output peripherals that display information with input devices that send data.

Distractor check: Students might pick A or D (Executes code or Debugs errors) assuming a development tool handles running or troubleshooting programs. Reasoning to the answer: A compiler converts high-level source code into machine code for execution. It doesn’t execute code, manage memory, or debug, which are separate processes. Common mistake: Assuming the tool that translates code is also responsible for executing or debugging it.

Distractor check: Option B (HTTP) is ubiquitous in web browsing, making it a common misguess for anyone mixing up web protocols with email protocols. Reasoning to the answer: SMTP (Simple Mail Transfer Protocol) handles email sending. FTP transfers files, HTTP serves web pages, and TELNET enables remote access. Common mistake: Confusing the protocol used for web browsing (HTTP) with the one dedicated to email transmission (SMTP).

Distractor check: Option A (Connect devices in a LAN) is tempting because networking hardware generally connects computers together. Reasoning to the answer: A router directs data between different networks (e.g., LAN to WAN) using IP addresses. LAN connections are for switches, storage is for servers, and encryption is for security protocols. Common mistake: Believing a router manages local area network connections instead of routing traffic between distinct networks.

Distractor check: Options like B, C, or D (HTML, SQL, CSS) are specialized web or query languages that students encounter frequently in web development. Reasoning to the answer: C supports structured programming with functions and control structures. HTML and CSS are markup/styling, and SQL is for database queries. Common mistake: Grouping web styling or database languages under structured procedural programming.

Distractor check: Options B, C, and D use plausible computing words like 'Program', 'Peripheral', or 'Processor' to trick students who only half-remember the acronym. Reasoning to the answer: CPU (Central Processing Unit) is the computer’s processor, executing instructions. Other options are not standard computing terms. Common mistake: Guessing a variation that includes peripheral or program instead of the core central processing unit.

Distractor check: Options A, B, and D (Merge Sort, Quick Sort, Heap Sort) are major sorting algorithms taught alongside insertion sort, often misattributed as universally superior. Reasoning to the answer: Insertion Sort is efficient for small datasets due to low overhead and O(n^2) complexity, outperforming Merge, Quick, or Heap Sort for few elements. Common mistake: Assuming complex divide-and-conquer algorithms are always faster regardless of dataset size.

Distractor check: Option A (Encrypts data) might look appealing if a student associates network infrastructure with overall system security. Reasoning to the answer: DNS (Domain Name System) translates domain names (e.g., google.com) to IP addresses for network communication. It doesn’t encrypt, compress, or manage email. Common mistake: Confusing name resolution services with data encryption or compression tools.

Distractor check: Options A, C, and D (Hard Disk, USB Drive, CD-ROM) are familiar storage media that students interact with daily, making them easy to confuse with internal working memory. Reasoning to the answer: RAM (Random Access Memory) is primary storage, volatile and used for active data. Hard disks, USB drives, and CD-ROMs are secondary, non-volatile storage. Common mistake: Mixing up secondary persistent storage drives with primary volatile memory.

Distractor check: Options B, C, and D use official-sounding administrative words like 'General', 'Global', or 'Instruction' to catch students guessing. Reasoning to the answer: GUI (Graphical User Interface) allows user interaction via visual elements like windows and icons, unlike the other non-standard terms. Common mistake: Selecting 'Global Unit Interface' or similar fabricated terminology.

Distractor check: Options B, C, and D (Web Browser, Text Editor, Database Manager) are common software applications that users interact with directly, causing confusion with system-level control. Reasoning to the answer: An Operating System (e.g., Windows) manages hardware resources like CPU and memory. Browsers, editors, and databases serve specific application roles. Common mistake: Confusing application-layer tools with the core operating system that manages underlying hardware.