Question 1

INTERNET DOMAINS — Country-code for New Zealand When writing website addresses with country-code top-level domains (ccTLDs), which two-letter code belongs to New Zealand?

Accepted Answer

Introduction / Context: Country-code top-level domains help identify geographic association on the Internet. Recognizing common ccTLDs is useful for IT support, digital marketing, and general knowledge tests. Given Data / Assumptions: The code must be an officially assigned two-letter ccTLD. New Zealand is the target country. We are not dealing with subdomains or provincial codes. Concept / Approach: New Zealand’s ccTLD is NZ, so domains end with .nz (for example, govt.nz or co.nz). This aligns with ISO 3166-1 alpha-2 codes used for ccTLD assignment. Step-by-Step Solution: Recall: New Zealand → NZ.Verify that NZ is listed among the options.Choose NZ and reject nonstandard codes. Verification / Alternative check: Domain registries and Internet governance resources list .nz as New Zealand’s ccTLD. Why Other Options Are Wrong: NW / NE / ZL / ND — not assigned as ccTLDs for New Zealand. Common Pitfalls: Guessing “ZL” from the letters in “Zealand.” ccTLDs follow ISO codes, not arbitrary letter selections. Final Answer: NZ

Question 2

SECURITY AWARENESS — Recognizing hoax viruses Which of the following is a well-documented hoax warning that circulated widely by e-mail, not a real computer virus or worm?

Accepted Answer

Introduction / Context: Hoax virus warnings spread fear and waste time by urging users to delete files or forward messages. Learning to recognize hoaxes reduces panic and helps focus on real cybersecurity threats. Given Data / Assumptions: We are choosing an example of a known hoax, not an actual piece of malware. E-mail chain letters often cited fake “brand-name” screensavers as deadly viruses. Real malware typically has technical identifiers and observed behavior. Concept / Approach: Classic hoaxes invoked recognizable companies (e.g., a “McDonalds screensaver”) and warned users to delete harmless system files or to forward the alert. Cyber hygiene recommends verifying threats via reputable security vendors and debunking resources before acting. Step-by-Step Solution: Scan options for brand-lured scare stories → “McDonalds screensaver.”Note others resemble names of real or plausible malware.Select the hoax example. Verification / Alternative check: Security vendor knowledge bases and hoax-detection sites list brand-themed screensaver warnings among famous hoaxes. Why Other Options Are Wrong: Alien.worm / Adolph — names fitting malware naming conventions; not established hoax archetypes.Merry Xmas — similar names have been used by actual malware campaigns.ILOVEYOU — a notorious, very real mass-mailing worm from 2000. Common Pitfalls: Forwarding unverified warnings. Always consult trusted advisories (e.g., CERT, major AV vendors) before deleting files or sharing alerts. Final Answer: McDonalds screensaver

Question 3

SEARCH LITERACY — Identifying a search engine Which of the following is a web search engine used to discover information across the Internet?

Accepted Answer

Introduction / Context: Search engines are gateways to information on the web. Distinguishing them from browsers, plugins, directories, and e-mail clients helps users pick the right tool for a task. Given Data / Assumptions: We are selecting a true search engine from a mixed list of software and services. Only one option conducts automated crawling/indexing and offers keyword search queries at scale. Some options are browsers or curated directories, not engines. Concept / Approach: Google is a search engine that uses crawlers (spiders) and ranking algorithms to return relevant results. Other items listed serve different roles: authoring tools, browsers, curated link lists, or communication software. Step-by-Step Solution: Identify which option performs automated indexing and query processing → Google.Exclude software that renders content (browsers) or creates content (plugins/authoring tools).Exclude curated directories that do not algorithmically crawl the web. Verification / Alternative check: Google’s public documentation describes web crawling, indexing, and ranking — the hallmarks of a search engine. Why Other Options Are Wrong: Macromedia Flash — multimedia authoring/runtime platform, not a search engine.Netscape — a web browser brand, not an engine.Librarians’ Index to the Internet — a curated directory of links, not a full crawler-based engine.Outlook — an e-mail and personal information manager. Common Pitfalls: Confusing browsers (which display the web) with search engines (which find content across the web). A browser can use any search engine as a default provider. Final Answer: Google

Question 4

Computer hardware fundamentals – identifying bus/slot standards used in AT-class systems Which of the following is NOT a type of expansion slot or bus design associated with IBM PC/AT–class architectures and their successors used to connect add-in c…

Accepted Answer

Introduction / Context: Expansion buses and slots are how desktop computers add capabilities such as graphics, storage controllers, and networking. IBM PC/AT–class systems and their descendants introduced multiple slot standards over time, while some acronyms in computing refer to components that are not buses at all. This question checks whether you can distinguish real bus/slot standards from unrelated hardware terms. Given Data / Assumptions: The focus is on bus/slot designs historically used with IBM PC/AT–class machines and compatibles. Options mix true expansion interconnects with a non-bus semiconductor device term. Only one option is not a bus/slot standard. Concept / Approach: Bus/slot standards include ISA (Industry Standard Architecture), EISA (Extended ISA), PCI (Peripheral Component Interconnect), and portable-card formats such as PCMCIA (also called PC Card). PROM, by contrast, stands for Programmable Read-Only Memory, which is a type of non-volatile memory device, not a motherboard interconnect. Step-by-Step Solution: List known PC/AT family buses: ISA, EISA, PCI are all valid expansion buses.Recognize PCMCIA as an expansion card standard used mainly in laptops, still a true expansion interface.Identify PROM as memory silicon, not an interconnect. Therefore, it is not a bus/slot design. Verification / Alternative check: Motherboard manuals and hardware histories show physical slots labeled ISA/EISA/PCI. PROMs appear as chips, not as slots, and are programmed once to store firmware or data. Why Other Options Are Wrong: ISA: 8/16-bit legacy bus used widely in AT systems. EISA: 32-bit extension of ISA used in high-end systems/servers. PCI: Popular local bus introduced in the 1990s, successor to ISA/EISA for many devices. PCMCIA: Laptop expansion card interface (Type I/II/III), still an expansion standard. Common Pitfalls: Confusing component acronyms (PROM, EPROM, EEPROM) with interconnects. Remember: buses are pathways and slots; memories are chips. Final Answer: PROM

Question 5

Computer security history – classic DOS virus identification This virus, famous for activating on Friday the 13th, infects both .EXE and .COM files and deletes any program executed on that date. What is its widely known name?

Accepted Answer

Introduction / Context: Before modern operating system protections, DOS-era file-infecting malware spread rapidly through floppy disks and early networks. Several classic viruses became notorious for their trigger conditions. Recognizing famous signatures helps in understanding malware taxonomy and historical incident response. Given Data / Assumptions: The virus infects both .EXE and .COM files. It activates specifically on Friday the 13th. On that date it deletes programs that are run. Concept / Approach: The described behavior matches the Jerusalem virus family (also called Friday the 13th). It originated in the late 1980s, infected executable formats, and had a destructive payload on the trigger date. Other listed malware are from different eras or have different behaviors. Step-by-Step Solution: Match the trigger: Friday the 13th is a hallmark of the Jerusalem family.Confirm file types: .COM and .EXE infection is consistent with classic DOS file infectors like Jerusalem.Eliminate options that belong to different platforms or payload characteristics. Verification / Alternative check: Virus encyclopedias and historical writeups describe Jerusalem’s Friday-the-13th destructive routine and its multi-file infection pattern. Why Other Options Are Wrong: Chernobyl (CIH): late-1990s Windows virus that overwrote flash BIOS on certain dates; not specific to Friday the 13th. Melissa: 1999 email macro virus that spread via Microsoft Office documents; no Friday-the-13th trigger. I Love You: 2000 email worm in VBScript; social engineering based, not a .COM/.EXE file infector. Michelangelo: triggered March 6; different signature and date. Common Pitfalls: Confusing similarly notorious names across decades. Always tie the identifying trigger (date) and file types to the correct family. Final Answer: Jerusalem

Question 6

Networking terminology – meaning of TTL In Internet Protocol (IP) networking and related systems, what does the abbreviation TTL stand for, representing a limit on a packet's or resource's lifetime?

Accepted Answer

Introduction / Context: TTL is a core parameter used in multiple computing contexts. In IP networking, it prevents packets from circulating indefinitely; in DNS, it dictates how long records may be cached. Understanding TTL helps troubleshoot routing loops, traceroute output, and cache behaviors. Given Data / Assumptions: The question concerns the expansion of the acronym TTL. We are focusing on networking usage (IP, DNS), though the term appears in other systems too. Exactly one option is the accepted standard expansion. Concept / Approach: TTL stands for Time To Live. In IP headers, TTL is a hop-limit value decremented by each router; when it reaches zero, the packet is discarded and an ICMP message may be sent. In DNS, TTL is a duration indicating how long a resolver can cache an RR set before refreshing. Step-by-Step Solution: Recall common networking abbreviations: TTL is universally “Time To Live”.Compare options, eliminating phrases that are not standard protocol terminology.Select the expansion recognized by RFCs and textbooks. Verification / Alternative check: IP packet structure diagrams show an 8-bit TTL field; DNS zone files contain TTL values like 300 seconds for caching policies. Why Other Options Are Wrong: Transparent Transfer Layer / Technical Talk Language / True Technology Lives / Transaction Trace Log: informal or unrelated phrases not used in IP specs. Common Pitfalls: Confusing TTL with hop count or with TCP timeouts; TTL is decremented per hop (or interpreted as hop limit in IPv6) and is distinct from transport-level timers. Final Answer: Time To Live

Question 7

Web research skills – finding curated, handpicked websites Which type of web-finding tool is best when you want sites that have been reviewed, organized, and recommended by humans rather than only ranked by algorithms?

Accepted Answer

Introduction / Context: Online discovery tools differ in how results are gathered and vetted. If you need quality, curated links—especially for academic overviews or authoritative resources—understanding which tool emphasizes human review is essential. Given Data / Assumptions: You want websites that have been handpicked and recommended. Tools considered include algorithmic search, meta-search, forums, and curated directories. There is exactly one best match for human-reviewed curation. Concept / Approach: Subject directories (sometimes called web directories) organize links by topic and rely on editors or communities to select, summarize, and categorize sites. Classic examples historically included curated librarian directories and academic gateways. Search engines crawl and index the entire web automatically; meta-search engines aggregate multiple search engines; discussion groups and social feeds are conversational, not systematically curated directories. Step-by-Step Solution: Identify the tool that explicitly involves human editorial selection: subject directories.Eliminate tools whose primary function is algorithmic indexing or conversation rather than curation.Choose “Subject directories.” Verification / Alternative check: Library and academic resource guides often maintain directories with annotated links; these are examples of human-vetted collections distinct from search engines. Why Other Options Are Wrong: Search engines: powerful breadth but not necessarily human-annotated. Meta-search engines: combine algorithmic results, still not curated. Discussion groups: useful for advice but unstructured and subjective. Social media timelines: ephemeral and ranking-driven, not stable curation. Common Pitfalls: Assuming first-page search results are equivalent to curation. Ranking signals do not replace expert selection and annotation. Final Answer: Subject directories

Question 8

In database technology, what is a Relational Database Management System (RDBMS) and what are some of its key features?

Accepted Answer

Introduction / Context: Relational Database Management Systems, or RDBMS, are widely used to store and manage structured data in applications ranging from banking to e commerce. Common examples include Oracle Database, MySQL, PostgreSQL and SQL Server. In technology interviews, candidates are often asked to define RDBMS and describe its core features. This question checks whether you understand the relational model and standard capabilities of an RDBMS. Given Data / Assumptions: The term RDBMS refers to systems based on the relational model proposed by E F Codd. Data is organised logically as relations, typically represented by tables. Users interact with the database using SQL or similar query languages. Concept / Approach: An RDBMS stores data in tables with rows representing records and columns representing attributes. Relationships between tables are implemented using primary keys and foreign keys, and integrity constraints help maintain consistency. RDBMS products also provide transaction management with ACID properties, ensuring that operations are atomic, consistent, isolated and durable. The correct option therefore needs to mention relational tables, SQL support, relationships and transactional features. Step-by-Step Solution: Step 1: Recall that relational databases use tables, rows and columns as the core storage structure.Step 2: Identify that RDBMS products support SQL for querying and manipulating data.Step 3: Recognise that keys and constraints enforce relationships and maintain data integrity, while ACID transactions ensure safe multi step operations.Step 4: Option A describes all these aspects clearly, mentioning the relational model, tables, SQL, keys, constraints and ACID transactions.Step 5: Options B, C and D do not describe relational databases at all, so option A is correct. Verification / Alternative check: Standard database textbooks define an RDBMS as a database management system that is based on the relational data model and uses a declarative query language such as SQL. They highlight features such as data independence, integrity constraints and support for concurrent transactions. Option A aligns with these definitions, confirming its accuracy as a summary of what an RDBMS is. Why Other Options Are Wrong: Option B describes a plain file system without the structure, query language or constraints that make up an RDBMS. Option C refers to a graphical tool for drawing network diagrams, which is unrelated to database management. Option D talks about operating systems in general, which can host databases but are not themselves RDBMS. Common Pitfalls: Some learners confuse RDBMS with generic DBMS and forget to mention the relational model and keys. Others mix up SQL with the database engine itself. It is also common to forget ACID properties when describing features. In interviews, always mention tables, SQL, keys and constraints and ACID transactions as the core features of RDBMS technology. Final Answer: A database management system based on the relational model that stores data in tables with rows and columns, supports SQL, enforces relationships through keys and constraints and provides ACID transactions.

Question 9

In the C programming language, what is a function prototype and what are its main advantages for compiling and using functions?

Accepted Answer

Introduction / Context: Function prototypes are an important concept in C programming. They appear at the top of source files or in header files and tell the compiler what a function looks like before its actual definition or calls appear. Understanding prototypes is essential for writing multi file programs, avoiding implicit declarations and catching type related errors at compile time rather than at run time. Given Data / Assumptions: The language considered is C, where function prototypes are commonly used. A function prototype must specify at least the function name, return type and parameter list. The compiler uses this information when checking function calls. Concept / Approach: A function prototype is a declaration that describes the interface of the function. It has the same form as the function header but ends with a semicolon and has no body. By placing this prototype before any calls, the compiler knows what types to expect for arguments and the return value. This prevents errors such as passing wrong types or wrong number of arguments. It also enables type conversions where appropriate. The correct option must mention declaration, parameter types and compile time checking. Step-by-Step Solution: Step 1: Recall that a typical function prototype in C looks like: int add(int a, int b);Step 2: Note that this line appears before main or in a header file and is distinct from the full definition which includes the body.Step 3: The main advantage is that the compiler can verify each call to add for correct argument count and types.Step 4: Option A states that a prototype is such a declaration and explains the benefit of compile time checking.Step 5: Options B, C and D describe behaviour that does not match the role of function prototypes, so option A is correct. Verification / Alternative check: If pre C89 style code omits prototypes, the compiler may assume default int return type and may not correctly check parameters. This often leads to warnings or undefined behaviour. Modern C standards require proper prototypes. Textbooks emphasise that prototypes improve type safety and make multi file compilation easier. Option A reflects this widely accepted explanation of prototypes and their advantages. Why Other Options Are Wrong: Option B sounds like the main function, which is a specific entry point, not a prototype. Option C suggests a temporary debugging copy, which is not how prototypes work. Option D confuses prototypes with macros or inline expansion, which are different features. Common Pitfalls: Beginners sometimes confuse function prototypes with definitions or think they are optional decoration. Others forget to update prototypes when changing function signatures, leading to mismatches. Always remember that a prototype is about the interface, not the implementation, and its main advantage is type checking at compile time. Final Answer: A declaration of a function that specifies its name, return type and parameter types before it is used, which allows the compiler to check calls for correct number and type of arguments.

Question 10

In web development, which of the following actions cannot be performed directly by client side JavaScript running in a browser for security reasons?

Accepted Answer

Introduction / Context: Client side JavaScript runs inside the user's browser and is limited by security rules called the same origin policy and sandboxing. While JavaScript can do many interactive tasks on web pages, it cannot directly access server resources such as database files without going through server side code. This question tests whether you can distinguish between tasks that are possible in client side scripts and those that require server side support. Given Data / Assumptions: JavaScript here refers to code executed in a browser, not Node.js on the server. The environment follows normal web security practices. We consider common operations around HTML forms and data storage. Concept / Approach: Client side JavaScript can read form values, validate them, show error messages and send data to the server using form submission or asynchronous requests. However, it cannot open or write to files on the server or manipulate the database directly. That responsibility belongs to server side technologies such as PHP, Java, Python or Node.js with appropriate database drivers. The correct option therefore must describe an action that would require direct server file or database access without server side code, which is not allowed from pure client side scripts. Step-by-Step Solution: Step 1: Check each option to see whether it involves only browser side activity or direct server side file or database access.Step 2: Option A describes sending form contents to a server side script, which is possible via form submission or fetch or Ajax.Step 3: Option C and option D describe validation and displaying error messages, which are classic use cases for client side JavaScript.Step 4: Option B talks about directly storing form contents into a database file on the server with no server side code, which is not possible because browser scripts cannot open server database files.Step 5: Therefore, option B is the correct answer because it describes something client side JavaScript cannot do. Verification / Alternative check: If client side scripts could write directly to server databases, any third party page or attacker could tamper with data simply by running JavaScript in a browser, which would be a serious security hole. Instead, all database operations must pass through authenticated server side logic. Documentation for web security emphasises that JavaScript in the browser can only communicate with the server over HTTP or HTTPS and cannot bypass server side protections. Option B violates this rule and is therefore impossible for pure client side code. Why Other Options Are Wrong: Option A is possible because sending data to the server is exactly what forms and asynchronous requests are designed to do. Option C is a standard practice where JavaScript checks field formats before submission. Option D is also a common behaviour where scripts update the page dynamically to show error messages or hints. Common Pitfalls: Beginners sometimes think that because JavaScript can send data to the server, it is directly writing to the database. In reality, the server decides what to do with the data. Another mistake is confusing client side JavaScript with server side JavaScript environments. When answering such questions, always think about where the code runs and what resources it can and cannot access. Final Answer: Directly storing a form's contents into a database file on the server without any server side code.

Question 11

In web technologies, what is Dynamic HTML (DHTML) and what are some important features that distinguish it from static HTML pages?

Accepted Answer

Introduction / Context: Dynamic HTML, often abbreviated as DHTML, is a term used to describe web pages that change interactively in the browser without requiring a full page reload from the server. Although the term is older and less used today, the underlying idea remains central to modern web development. Understanding DHTML helps clarify how HTML, CSS and JavaScript work together to create interactive user experiences. Given Data / Assumptions: DHTML is not a separate language but a combination of technologies. Browsers provide a Document Object Model, or DOM, to allow scripts to manipulate page elements. The goal is to update content and presentation dynamically on the client side. Concept / Approach: A DHTML page uses HTML to define structure, Cascading Style Sheets to control presentation, JavaScript to program behaviour and the DOM to access and modify elements. With these tools, the page can respond to events such as clicks and mouse movements, change styles, show or hide elements, and update content without contacting the server for every change. The correct option must therefore describe DHTML as a combination of technologies that enables dynamic manipulation of web pages in the browser. Step-by-Step Solution: Step 1: Recall that DHTML is an umbrella term that includes HTML, CSS, JavaScript and DOM scripting.Step 2: Recognise that its main feature is the ability to change page content and appearance interactively without reloading.Step 3: Option A presents DHTML exactly this way, mentioning HTML, CSS, JavaScript, DOM and dynamic updates based on user actions.Step 4: Options B, C and D describe unrelated technologies and do not refer to interactive pages.Step 5: Therefore, option A is the correct definition and feature summary for DHTML. Verification / Alternative check: If you look at classic examples of DHTML, they include animated menus, expanding sections and drag and drop elements implemented purely on the client side. All such features rely on JavaScript modifying HTML elements and CSS styles through the DOM. No separate language called DHTML exists. This confirms that any correct definition must emphasise the combination of technologies, as option A does. Why Other Options Are Wrong: Option B incorrectly suggests that DHTML is a new mobile only version of HTML. Option C confuses DHTML with server side scripting, which runs on the server rather than in the browser. Option D describes a file format for images or animations, which is not DHTML. Common Pitfalls: Some learners think that DHTML is an outdated or separate language instead of a concept. Others mix up dynamic pages that reload from the server with dynamic behaviour entirely in the browser. To avoid confusion, remember that DHTML refers specifically to client side techniques that update the page in place using scripts and styles. Final Answer: A combination of HTML, CSS, JavaScript and the Document Object Model that allows web pages to change content, style and layout dynamically in response to user actions without reloading the whole page.

Question 12

In data structures, what is the main difference between a stack and an array when they are used to store elements in memory?

Accepted Answer

Introduction / Context: Arrays and stacks are fundamental structures used to hold collections of elements in memory. Many interview and exam questions ask for the difference between them to check whether you understand not only memory layout but also the operations allowed on each structure. This question focuses on how access patterns and usage rules differ between a general array and a stack abstract data type. Given Data / Assumptions: An array is a contiguous block of memory with indexed elements. A stack is an abstract data type that can be implemented using arrays or linked lists. Stacks follow the Last In First Out, or LIFO, principle for insert and delete operations. Concept / Approach: In an array, any element can be accessed directly by its index in constant time, and the structure does not impose rules on where you insert or remove elements, though such operations may shift data. In a stack, operations are restricted to one end, called the top. Push adds an element to the top and pop removes the most recently added element. This restriction defines the stack behaviour. Therefore, the correct option must explain free random access in arrays versus restricted LIFO access in stacks. Step-by-Step Solution: Step 1: Recall that arrays support random access and can be used in many different ways.Step 2: Recall that stacks expose only push, pop and sometimes peek operations on the top element.Step 3: Option A states that arrays allow random index based access and stacks are restricted to one end with LIFO discipline.Step 4: Option B introduces a false restriction on data type for stacks, and option C makes incorrect statements about automatic resizing.Step 5: Option D wrongly claims there is no difference, so option A is correct. Verification / Alternative check: You can check this by considering common uses. A stack is often used for function call management and undo operations, where you always remove the most recent element. An array is used for general storage such as an array of scores or names where you frequently access arbitrary positions. Implementation wise, a stack may use an array internally, but the interface imposed on the programmer is more restricted than direct array access. This confirms the description given in option A. Why Other Options Are Wrong: Option B is wrong because stacks can store any data type depending on the implementation and programming language. Option C is incorrect because arrays do not automatically resize in many languages and stacks may be implemented as dynamic structures. Option D ignores the conceptual differences between the two structures. Common Pitfalls: Students sometimes confuse how something is implemented with what operations are allowed. They may say that a stack is an array, when more precisely a stack can be implemented by an array. Remember that an abstract data type is defined by permitted operations and behaviour, not by a specific implementation detail. Final Answer: An array is a linear collection that allows random access to any element by index, while a stack is a restricted structure that allows insertion and removal only at one end using a Last In First Out discipline.

Question 13

In SQL, which operator is commonly used in a WHERE clause to perform pattern matching on character data?

Accepted Answer

Introduction / Context: Pattern matching on strings is a frequent requirement in database queries. For example, you might want all customers whose names start with a certain letter or all products that contain a specific word in their description. SQL provides operators to support such pattern based searches. This question asks you to identify the standard operator used in WHERE clauses for simple pattern matching on character data. Given Data / Assumptions: The database language considered is SQL. We are working with character or text columns. The goal is to match patterns such as starting with or containing a substring. Concept / Approach: The LIKE operator in SQL allows you to specify patterns using wildcard characters such as percent and underscore. For example, name LIKE 'A%' matches any value starting with A, and name LIKE '%son' matches any value ending with son. EXISTS and BETWEEN operators have different purposes: EXISTS checks for the existence of rows in a subquery and BETWEEN checks whether a value lies in a range. Therefore, LIKE is the correct choice for pattern matching. Step-by-Step Solution: Step 1: Recall that pattern matching typically uses wildcard characters like percent and underscore.Step 2: Remember that in SQL, these wildcards are used with the LIKE operator in WHERE conditions.Step 3: Option A explicitly names the LIKE operator.Step 4: Option B, EXISTS, is used to test whether a subquery returns at least one row and is not for pattern matching.Step 5: Option C, BETWEEN, checks if a value lies between two given values, which is different from string patterns, while option D is incorrect because a suitable operator does exist. Verification / Alternative check: Examples from any SQL tutorial show statements such as SELECT * FROM employees WHERE first_name LIKE 'J%'; to find employees whose first name starts with J. There is no way to perform this simple pattern based filtering with BETWEEN or EXISTS. This practical usage confirms that LIKE is the required operator for basic pattern matching on text values. Why Other Options Are Wrong: Option B, EXISTS, evaluates to true if the subquery returns any rows and is commonly used for correlated subqueries. Option C, BETWEEN, is generally applied to numeric or date fields to check ranges and not for substring matching. Option D is wrong simply because the LIKE operator is available for this purpose. Common Pitfalls: Beginners sometimes confuse LIKE with equality or try to use range conditions for partial text matching. Another pitfall is forgetting that LIKE with wildcards can be slower on large tables if indexes are not used properly. However, for exam purposes, it is enough to remember that LIKE is the keyword for simple pattern matching in SQL WHERE clauses. Final Answer: LIKE operator

Question 14

Which statement best describes how web pages on the World Wide Web are organised and connected?

Accepted Answer

Introduction / Context: The World Wide Web is one of the most visible parts of the internet. It consists of millions of web pages that users access through browsers. Understanding how these pages are stored and connected helps clarify basic concepts in internet and web technology. This question asks you to identify the statement that best describes the organisation and linkage of web pages on the World Wide Web. Given Data / Assumptions: Web pages are retrieved via HTTP or HTTPS protocols over the internet. They are stored on many different web servers around the world. Hyperlinks allow users to move between related pages easily. Concept / Approach: Each website typically runs on a web server, which may be located anywhere in the world and connected to the internet. Web pages are written in HTML or other markup languages and made available through URLs. Hyperlinks inside pages point to other pages on the same or different servers, creating a web like structure. The correct option must therefore mention distribution across many computers and linking via hyperlinks, not central storage or complete lack of markup. Step-by-Step Solution: Step 1: Recall that there is no single central computer for all web pages; instead, many servers host different sites.Step 2: Remember that pages are connected by hyperlinks which allow clicking from one page to another.Step 3: Option A says that pages reside on many computers connected through the internet and are linked using hyperlinks, which reflects this reality.Step 4: Option B claims that all pages reside on a single central computer, which is false.Step 5: Options C and D deny network access or the use of HTML, which contradicts basic facts about the web, so option A is correct. Verification / Alternative check: If you type different URLs into a browser, you connect to different servers as shown by different domain names. The browser fetches HTML content from those servers and follows hyperlinks embedded in the pages. This everyday experience confirms that web pages are distributed and interconnected, matching the description in option A. Why Other Options Are Wrong: Option B imagines a centralised web, which would be a single point of failure and does not match how the real web is built. Option C ignores the network nature of the web by claiming that pages are only on local drives. Option D claims that web pages are always created without HTML or any markup, which conflicts with the fundamental role of HTML in the World Wide Web. Common Pitfalls: Some learners confuse the internet, which is the underlying network of networks, with the World Wide Web, which is the system of linked documents accessed over that network. Others underestimate the importance of hyperlinks in making navigation possible. Always remember that the web is a distributed, hyperlinked collection of documents stored on many servers worldwide. Final Answer: They reside on many computers connected through the internet and are linked to each other using hyperlinks so that users can navigate from one page to another.

Question 15

In hash table design, which option correctly lists two main types of collision resolution techniques and example methods used in each type?

Accepted Answer

Introduction / Context: Hash tables are widely used for fast insertion and lookup of key value pairs. However, collisions occur when different keys hash to the same table index. Collision resolution techniques are strategies used to handle these collisions while preserving good average performance. Interview and exam questions often ask you to name the main categories of collision resolution and to give typical methods in each category. This question focuses on that conceptual understanding in the context of data structures and algorithms. Given Data / Assumptions: We are discussing hash tables used in memory based data structures, not cryptographic hash functions. Two widely taught categories are open addressing and separate chaining. Typical methods in open addressing include linear probing, quadratic probing and double hashing. Concept / Approach: In open addressing, all elements are stored directly in the hash table array. When a collision occurs, the algorithm probes other slots according to a fixed rule until it finds an empty position. Linear probing checks the next slot, quadratic probing uses a quadratic step, and double hashing uses a second hash function to determine the probe sequence. In separate chaining, each cell of the hash table points to a linked list or another secondary structure where colliding elements are stored. The correct option must mention both categories and give appropriate examples of methods. Step-by-Step Solution: Step 1: Recall from theory that the two main types of collision resolution are open addressing and chaining.Step 2: List typical open addressing methods such as linear, quadratic and double hashing.Step 3: Recognise that chaining involves attaching a list of keys to each bucket to hold colliding entries.Step 4: Option A describes open addressing with its probing methods and separate chaining using linked lists.Step 5: Options B, C and D mention algorithms or techniques that do not represent standard hash collision resolution methods, so option A is correct. Verification / Alternative check: Data structures textbooks classify collision resolution schemes exactly in this way. They show diagrams of hash tables using linear probing and of hash tables where each slot refers to a chain of nodes. Sorting algorithms and tree structures can be used for other purposes, but they are not the primary names used for hash collision resolution categories. This confirms that option A reflects the standard classification. Why Other Options Are Wrong: Option B lists sorting algorithms, which are not designed to resolve hash collisions. Option C lists tree based methods without mentioning that trees are usually separate structures rather than primary hash collision resolution categories. Option D refers to random numbers and encryption, which may be used in hash function design but are not collision resolution techniques in the usual sense. Common Pitfalls: Students sometimes remember the names of individual methods like linear probing but forget the categories they belong to. Others confuse the hash function design with collision handling. To avoid mistakes, keep clear that collision resolution in hash tables is mainly about open addressing versus chaining, with probing rules as subtypes of open addressing. Final Answer: Open addressing techniques such as linear probing, quadratic probing and double hashing, and separate chaining techniques where each table slot points to a linked list of entries.

Question 16

In standard SQL, which query correctly displays the current date returned by the database using the CURRENT_DATE function?

Accepted Answer

Introduction / Context: Most relational databases provide built in functions to return the current date and sometimes the current date and time. Knowing the standard SQL way to request the current date is useful for writing portable queries that run on different database systems. This question focuses on the CURRENT_DATE function defined in the SQL standard and tests whether you can identify the correct syntax to display the current date. Given Data / Assumptions: The database supports standard SQL syntax. The goal is to display the current date as returned by the server. CURRENT_DATE is used as a function or special value that returns today's date. Concept / Approach: In standard SQL, CURRENT_DATE is an ANSI SQL function like CURRENT_TIME and CURRENT_TIMESTAMP. It can be selected without a FROM clause in many systems or with a dummy table in some implementations. The simplest form in many databases is SELECT CURRENT_DATE;. Other options in the list, such as SYSDATE FROM dual, are specific to particular platforms like Oracle and are not the standard portable answer requested in the question. Therefore, the correct choice is the query that uses CURRENT_DATE directly. Step-by-Step Solution: Step 1: Recall that the SQL standard provides CURRENT_DATE to fetch today's date.Step 2: Identify the option that uses this name correctly in a SELECT statement.Step 3: Option A is SELECT CURRENT_DATE; which is the canonical form in many SQL engines and matches the standard.Step 4: Option B uses SYSDATE FROM dual, which is Oracle specific. Option C uses NOW without parentheses and a dummy table, which is not standard. Option D uses DATE() against a table, which does not necessarily return the current date.Step 5: Choose option A as the correct standard SQL query. Verification / Alternative check: Documentation for PostgreSQL, MySQL and other systems shows examples where CURRENT_DATE can be used directly in a SELECT statement. In PostgreSQL you can run SELECT CURRENT_DATE; and in MySQL you can use SELECT CURRENT_DATE; or SELECT CURDATE();. Although many systems also support proprietary functions, CURRENT_DATE is the most portable across compliant databases, which is why it is highlighted in standard focused exam questions. Why Other Options Are Wrong: Option B is valid in Oracle where dual is a special dummy table and SYSDATE returns the system date and time, but it is not standard and fails on databases that do not have dual. Option C uses NOW incorrectly and is incomplete or non standard without parentheses, and NOW is not part of the core SQL standard. Option D misuses DATE() on a specific table and would depend on the column being used, so it does not represent a general way to get the current date. Common Pitfalls: Many students memorise platform specific functions such as GETDATE(), SYSDATE or NOW() and then forget which one is portable. In certification exams that emphasise generic SQL, questions often prefer the standard CURRENT_DATE syntax. To reduce confusion, remember that CURRENT_DATE, CURRENT_TIME and CURRENT_TIMESTAMP are part of the SQL standard and are safe answers when cross platform behaviour is discussed. Final Answer: SELECT CURRENT_DATE;

Question 17

In SQL, which query correctly finds the number of employees grouped by gender whose date of birth is between 1 January 1960 and 31 December 1975, inclusive?

Accepted Answer

Introduction / Context: Grouping and filtering are core skills in SQL. Many business reports need counts of employees by categories such as gender or department, filtered by conditions like date of birth ranges. This question checks your ability to combine a WHERE clause with a BETWEEN condition on dates and a GROUP BY clause on gender. Understanding the correct ordering of clauses and the meaning of BETWEEN is essential for writing accurate queries. Given Data / Assumptions: There is an employees table with at least two columns: gender and dob (date of birth). Dates are stored in a standard format such as YYYY-MM-DD. The requirement is to include employees born from 1 January 1960 to 31 December 1975, both dates inclusive. Concept / Approach: The BETWEEN operator in SQL is inclusive at both ends, so dob BETWEEN '1960-01-01' AND '1975-12-31' selects all rows where dob is on or between these dates. To count employees by gender, we select gender and COUNT(*) and then group by gender so that one row is produced per gender with the corresponding count. The correct query therefore needs SELECT gender, COUNT(*), a WHERE clause with the correct BETWEEN condition and a GROUP BY gender clause. Step-by-Step Solution: Step 1: Identify the required columns in the result: gender and count of employees per gender.Step 2: Form the WHERE condition to restrict dob to the inclusive range between 1960-01-01 and 1975-12-31.Step 3: Add GROUP BY gender so that counts are calculated separately for each gender value.Step 4: Option A writes exactly this: SELECT gender, COUNT(*) FROM employees WHERE dob BETWEEN '1960-01-01' AND '1975-12-31' GROUP BY gender;.Step 5: Options B, C and D misuse the date conditions or omit the grouping and counting logic, so option A is correct. Verification / Alternative check: To verify, imagine a small sample table with a few rows and manually apply the condition. Any employee born in 1965 should be included, and the same for 1970 or exactly on 1960-01-01 or 1975-12-31. The BETWEEN clause in option A includes those boundary dates. Option B reverses the range and uses strict inequalities, which will select no rows. Option C only includes two exact dates, ignoring the full interval. Option D does not count employees, it just returns multiple rows containing gender values. Why Other Options Are Wrong: Option B uses dob greater than 1975-12-31 and less than 1960-01-01 in the same condition, which can never be true for any row, and therefore returns zero results. Option C restricts the selection to employees whose dob matches exactly the two dates, not the full range. Option D selects gender only and does not perform any aggregation, so it does not satisfy the requirement of counting employees by gender. Common Pitfalls: Common mistakes include forgetting the GROUP BY clause when using aggregate functions, reversing the order of dates in BETWEEN, or misunderstanding that BETWEEN is inclusive. Some developers also hard code dates in formats that do not match the database settings, causing unexpected results. For exam and interview questions, always write dates in a clear format like YYYY-MM-DD and double check that the WHERE condition matches the verbal requirement. Final Answer: SELECT gender, COUNT(*) FROM employees WHERE dob BETWEEN '1960-01-01' AND '1975-12-31' GROUP BY gender;

Question 18

In a typical web environment, JavaScript code embedded in an HTML page is interpreted and executed primarily on which side?

Accepted Answer

Introduction / Context: JavaScript is a core technology of the web alongside HTML and CSS. In its most common use, JavaScript runs inside the browser to add interactivity to web pages. Interview questions often test whether candidates understand where JavaScript is executed in the classic client server model. This question focuses on the typical scenario of JavaScript embedded in HTML pages viewed in a standard web browser. Given Data / Assumptions: We are considering traditional client side JavaScript, not server side environments such as Node.js. HTML pages are loaded into a web browser on the user's device. JavaScript code is interpreted by a JavaScript engine integrated into the browser. Concept / Approach: In the client server model, the server delivers HTML, CSS and JavaScript files to the client. Once received, the browser parses the HTML, applies styles and runs any JavaScript using its built in engine. The code manipulates the Document Object Model to update the page, respond to events and send requests back to the server when needed. Therefore, JavaScript embedded in web pages is interpreted on the client side, which typically means the user's browser on their device. Step-by-Step Solution: Step 1: Recall that browsers such as Chrome, Firefox and Edge contain JavaScript engines like V8 or SpiderMonkey.Step 2: These engines interpret and execute scripts included in HTML pages after they are downloaded from the server.Step 3: This work happens on the client device, not on the web server itself.Step 4: Option C, client, correctly identifies where the code is interpreted in this typical scenario.Step 5: Options A, B and D do not match the standard behaviour of client side JavaScript, so option C is correct. Verification / Alternative check: If you disable JavaScript in your browser settings, client side scripts stop running even though the server still sends the same HTML and JS files. This shows that execution is taking place on the client. Server side scripts such as PHP or Python run on the server before the page is sent. The separation of responsibilities between server and client in web architecture reinforces that classic JavaScript in HTML pages is interpreted on the client side. Why Other Options Are Wrong: Option A, server, describes environments where scripts are executed on the server, which is true for some technologies but not for standard client side JavaScript in HTML pages. Option B, object, is not a side in the client server model and does not answer the question. Option D, none of the above, is wrong because there is a clear correct answer among the options. Common Pitfalls: Confusion may arise because JavaScript can also run on the server in platforms such as Node.js. In exam questions, however, unless server side JavaScript is explicitly mentioned, you should assume the classic browser context. Pay attention to words like embedded in an HTML page and web browser to guide your answer to client side execution. Final Answer: Client

Question 19

In client side web scripting, what is the correct JavaScript syntax to write the text Hello World into the current HTML document?

Accepted Answer

Introduction / Context: This question checks basic familiarity with JavaScript syntax and the difference between JavaScript and other programming languages. Beginners often confuse JavaScript syntax with that of Java or server side languages. A very common example in tutorials is writing Hello World into the web page using JavaScript. Knowing the correct syntax helps confirm that you understand the context in which the code runs and the correct object and method names. Given Data / Assumptions: The environment is client side JavaScript running in a browser. We want to output the text Hello World to the HTML document. The method must be valid JavaScript, not Java or other language syntax. Concept / Approach: In JavaScript, the global document object represents the current HTML document. The document.write method can output a string directly into the document stream. The correct call uses the method name on the document object and passes the text in quotes. System.out.println is a Java method used in console applications, println alone is not defined by default in JavaScript and response.write is associated with some server side environments, not client side scripts. Therefore, the correct answer uses document.write with the desired string. Step-by-Step Solution: Step 1: Identify that we are working with JavaScript in a browser, not with Java or ASP.Step 2: Recall that document.write("Hello World"); is a textbook example of writing to the page in JavaScript.Step 3: Option C matches this syntax exactly, using the document object and write method with the string argument.Step 4: Option A is Java syntax for printing to the console, not JavaScript.Step 5: Option B is incomplete and does not refer to any defined function, and option D relates to server side scripting, so option C is correct. Verification / Alternative check: If you include a script tag in an HTML page and write document.write("Hello World"); inside it, loading the page in a browser will display Hello World at the point where the script executes. Trying System.out.println in the same context raises an error because System is not defined in JavaScript. This direct experiment confirms that document.write is the correct method to use in this simple example. Why Other Options Are Wrong: Option A belongs to the Java language, not JavaScript, even though their names are similar. Option B omits the object that owns the method and is not standard JavaScript. Option D corresponds to response.write in some server side technologies such as classic ASP, which are executed on the server, not in the browser. Common Pitfalls: A very common mistake is to confuse Java with JavaScript because of the similar names. Another pitfall is to assume that functions like println are globally available, which is not true in JavaScript. While document.write is rarely used in modern applications for dynamic updates, it remains a simple teaching example and often appears in introductory interview questions. Final Answer: document.write("Hello World");

Question 20

In programming, which parameter passing mechanism is generally more effective when a function needs to modify a large object passed from the caller?

Accepted Answer

Introduction / Context: Different programming languages support different parameter passing mechanisms. When functions receive parameters, the way values are passed affects both performance and the ability to modify the original arguments. This question focuses on the scenario where a function needs to modify a large object, such as a large structure or class instance, and asks which mechanism is generally more effective in that case. The answer is relevant in languages like C++ that distinguish clearly between call by value and call by reference. Given Data / Assumptions: The object being passed is large enough that copying it is relatively expensive. The function is expected to modify the original object, not just a local copy. We are considering common language designs where references or pointers allow functions to work with the original data. Concept / Approach: Under call by value, the function receives a copy of the argument, so modifications inside the function do not affect the original and copying may be expensive for large objects. Under call by reference, the function receives an alias or reference to the original object, so no full copy is made and any changes are applied directly to the caller's data. Call by pointer is similar in effect but uses explicit pointers and dereferencing; the question asks generally which mechanism is more effective in the described scenario, and most textbooks highlight call by reference for this purpose in modern high level languages. Step-by-Step Solution: Step 1: Consider the cost of copying large objects when using call by value.Step 2: Consider the necessity of modifying the original object, which is not possible with pure call by value without returning the object.Step 3: Recognise that call by reference passes an alias to the existing object without copying and allows direct modification.Step 4: Option B, call by reference, matches this reasoning and is commonly recommended for functions that must modify large arguments.Step 5: Option C, call by pointer, can achieve similar results but usually requires more careful syntax; option A does unnecessary copying, and option D is not meaningful as an answer. Verification / Alternative check: In C++, many function signatures use references for parameters that are to be modified or are large objects, for example void updateOrder(Order and order). This avoids copying and clearly communicates that the function will work with the caller's data. Guides on performance and memory usage recommend passing large objects by reference or by reference to const, rather than by value. This practice confirms that call by reference is considered more effective in the scenario described. Why Other Options Are Wrong: Option A, call by value, forces a full copy of the object and prevents direct modification of the original, making it less efficient and less suitable for this use case. Option C, call by pointer, can be effective but typically introduces additional complexity with null checks and explicit dereferencing; the more modern and straightforward recommendation in many languages is call by reference. Option D does not answer the question and suggests no mechanism, which is not helpful. Common Pitfalls: Students sometimes assume that call by value is always better because it seems safer, ignoring performance costs for large objects. Others treat pointers and references as identical in all languages, which is not accurate. A good rule of thumb in C++ is to use references for parameters that should be modified or for large objects to avoid copying, reserving call by value for small types like integers where copying is cheap. Final Answer: call by reference

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