WAEC SSCE - Data Processing - 2019

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In distributed database management systems, breaking a relation into smaller relations is known as fragmentation. Fragmentation involves dividing a single database relation (or table) into multiple smaller relations (or sub-tables) based on specific criteria, such as geographical location, functional requirements, or access frequency. The smaller relations can then be stored and managed across multiple nodes in a distributed database system. Fragmentation is done to achieve better performance, scalability, and availability of data in a distributed environment. By dividing data into smaller subsets, queries can be executed faster and with reduced network traffic, as only the relevant subsets need to be accessed. There are different types of fragmentation, such as horizontal fragmentation (dividing rows of a table), vertical fragmentation (dividing columns of a table), and hybrid fragmentation (combining horizontal and vertical fragmentation). The choice of fragmentation strategy depends on the specific needs and requirements of the distributed database system.

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Dampen material is typically used to clean electronic devices without causing damage from water or other liquids. Therefore, it is generally safe to use dampen material on keyboards and mice, as these devices can get dirty and require cleaning. It is also safe to use dampen material on screens, as long as the material is not too wet and is applied gently to avoid scratching the screen. However, it is not recommended to use dampen material on DVD lenses. DVD lenses are sensitive and can easily be damaged by liquid, including dampen material. Instead, specialized cleaning solutions and tools should be used to clean DVD lenses. Therefore, the device on which dampen material should not be used is DVD lens.

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One unique feature of an index file is that it contains a reference number. An index file is a data structure that stores references to data records in a database or file system. The reference number serves as a pointer to the actual location of the data record, allowing for faster and more efficient access to the data. When a user performs a search or query on a database, the index file is used to quickly locate the relevant data records, based on the reference number. This eliminates the need to search through the entire database, which can be time-consuming and resource-intensive. The reference number in an index file can be generated in various ways, depending on the type of database or file system being used. Some databases use a sequential number, which is assigned to each data record in the order it is added to the database. Other databases use a relative number, which is based on the position of the data record within a specific block or page of the database. In summary, the unique feature of an index file is that it contains a reference number, which serves as a pointer to the actual location of data records in a database or file system. This allows for faster and more efficient access to data, particularly when performing searches or queries on large databases.

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In computing, ergonomics is a term associated with safety measures. Specifically, it refers to the design and arrangement of computer equipment and workstations in a way that minimizes physical strain and discomfort, and reduces the risk of repetitive strain injuries (RSIs) and other musculoskeletal disorders (MSDs) that can occur from prolonged computer use. Good ergonomic design can include features like adjustable chairs and desks, proper keyboard and mouse placement, and adequate lighting and ventilation to create a comfortable and healthy working environment for computer users.

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A chart is a graphical representation of data. It is a way to visually display information, making it easier to understand and interpret. Charts can come in many forms, such as bar charts, line charts, pie charts, etc. Each type of chart is used to represent data in a unique way and helps to highlight specific patterns or trends within the data. By using a chart, you can quickly grasp the key information contained within the data and make informed decisions based on that information.

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The process of gathering facts and statistics from different sources is known as data collection. This involves collecting information from various sources, such as surveys, interviews, databases, and online sources. The collected data may be in the form of numbers, text, or images, and it is usually gathered for a specific purpose or research question. Once the data has been collected, it can be analyzed and interpreted to derive insights and draw conclusions. Collation and retrieval are related steps in the data collection process, where the collected data is organized and stored for future use.

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A Word document can have a file extension of .doc, .docx, or .rtf, but not .jpg. The .doc and .docx file extensions are both used for Microsoft Word documents. The .doc format is the older version of Word documents, while the .docx format is the newer, more commonly used version. The .rtf file extension is short for Rich Text Format, and is a type of file that can be opened by many different word processing programs. However, the .jpg file extension is used for image files, not Word documents. JPEG is a common image format used for photos and other digital graphics. Therefore, a Word document cannot have a .jpg file extension.

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The file organization that requires a primary key is the indexed file organization. In indexed file organization, the data is stored in a primary file, and an index file is created to keep track of the location of each record in the primary file. The index file contains a list of keys and their corresponding record pointers, which are used to access the actual data in the primary file. A primary key is required in indexed file organization because it uniquely identifies each record in the primary file. This key is used to build the index file, and it must be unique for each record to ensure that the index file accurately maps the location of each record in the primary file. Without a primary key, it would be difficult to search for a specific record in the primary file or maintain the integrity of the index file. In summary, the indexed file organization requires a primary key because it relies on the uniqueness of the key to accurately map the location of each record in the primary file.

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The malware that appears as a harmless object but attacks its victims at the slightest opportunity is called a "Trojan horse". It is named after the wooden horse that was used by the Greeks to enter the city of Troy in ancient mythology. Trojan horses are malicious software programs that are disguised as legitimate programs, such as games or utility software. When a victim downloads or installs the Trojan horse, it can carry out a variety of attacks, such as stealing personal information, modifying or deleting files, and giving hackers unauthorized access to the victim's computer. Unlike worms, which can spread on their own, Trojan horses require the victim to execute them. Macro viruses are viruses that infect documents, and logic bombs are programs that are designed to execute a malicious action at a specific time or under certain conditions.

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The service you are referring to is teleconferencing. It is a way of holding a meeting with people in different locations by using telecommunication devices such as phones, computers or video conferencing systems. This allows participants to communicate with each other in real-time, hear each other's voices, see each other's faces, and share presentations and other materials as if they were in the same room. Teleconferencing is a convenient and cost-effective way to bring people together for meetings, without the need for travel.

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The MS PowerPoint feature that can be used to change the appearance of the entire presentation is the "Design template" option. This feature allows you to select a pre-designed template or create your own custom template that will be applied to all slides in your presentation. The design template can include background colors or images, font styles, bullet styles, and other design elements that will give your presentation a cohesive look and feel. By using a design template, you can save time and ensure that your presentation has a consistent and professional appearance.

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The shortcut key combination for adding a new tab in Figure 3 is Ctrl + T. This combination of keys allows you to quickly add a new tab in the figure, without having to go through a menu or other steps. By pressing Ctrl + T, a new tab will be created and you can start using it right away. This shortcut is a convenient and efficient way to manage multiple tabs in the figure, saving you time and effort.

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Ensuring the correctness and consistency of data is referred to as data integrity. Data integrity is the process of maintaining the accuracy, completeness, and consistency of data throughout its entire lifecycle. Data integrity is essential for any organization that relies on data to make decisions and drive business operations. Without data integrity, there is a risk that data can be corrupted, incomplete, or inaccurate, leading to poor decision-making, inefficiencies, and potential legal or regulatory issues. To ensure data integrity, organizations need to implement processes and technologies that prevent unauthorized access, tampering, or modification of data. This includes data backup and recovery systems, access controls, encryption, and data validation checks. In summary, data integrity refers to the process of ensuring the accuracy, completeness, and consistency of data throughout its lifecycle, which is crucial for effective decision-making and efficient business operations.

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Dust from the system unit casing can be removed using an antistatic wipe or an static wipe. Antistatic wipes and static wipes are specially designed cloths that are used to clean electronic equipment without leaving behind any residue or static charge that could harm the equipment. They are safe to use on the casing of a computer system unit and can effectively remove dust and other debris. Cotton wool and a wet cloth are not recommended for cleaning the system unit casing as they can leave behind fibers or residue that could damage the equipment or cause a short circuit. Additionally, using a wet cloth could also potentially damage the electrical components inside the system unit.

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The information transmission medium from location A to location B in space is called "wireless transmission". This means that information, such as data or signals, is sent from one location to another without the use of physical wires or cables. Instead, wireless transmission uses electromagnetic waves, such as radio waves, to carry the information through the air or space. This method of transmission is commonly used for communication technologies such as Wi-Fi, Bluetooth, and cellular networks. It allows for convenient and flexible communication between devices, as no physical connections are required.

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The best way to prevent the effect of viruses is by installing and updating antivirus software. Antivirus software is designed to detect, prevent and remove harmful software such as viruses, malware, and spyware from your computer. It works by scanning your computer regularly for any signs of these types of threats and taking action to remove them. Updating the antivirus software regularly ensures that it can detect the latest viruses and protect your computer from them. Additionally, being cautious when opening emails and attachments, downloading software from trusted sources, and keeping your operating system and software up-to-date can also help to prevent virus infections.

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The program that enables the computer hardware to communicate and function effectively is called the operating system. An operating system is a software program that manages computer hardware resources, such as the CPU, memory, and storage devices, and provides common services for computer programs. It acts as a mediator between the computer hardware and the user or application software. Without an operating system, the computer hardware would not be able to function properly, and the user or application software would not be able to access or use the computer's resources effectively.

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The correct order of invention from the earliest to the latest among the given ICT tools is: - Radio, cell phone, satellite, internet Radio was the first ICT tool invented, and it was used for broadcasting news and entertainment to the masses. The cell phone was invented later, which made it possible for people to communicate with one another wirelessly. After that, satellites were invented, which made it possible to transmit data over long distances. Finally, the internet was invented, which made it possible for people to connect with one another and share information globally.

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The use of transistors in circuits was a major advancement in the "second generation computers". Transistors are small electronic devices that can amplify and switch electronic signals. They are much smaller, more reliable, and more efficient than the vacuum tubes used in the first generation computers. The second generation of computers, which emerged in the late 1950s and early 1960s, used transistors instead of vacuum tubes. This allowed computers to be smaller, faster, and more reliable than their predecessors. The use of transistors also led to a significant reduction in the power consumption of computers, making them more affordable to run. In addition to the use of transistors, the second generation of computers also saw the development of magnetic core memory, which provided a more efficient way of storing data than the magnetic drum memory used in first generation computers. Overall, the second generation of computers represented a major leap forward in computer technology, paving the way for further advancements in the following generations.

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Bluetooth is the technology that enables wireless connectivity in a Personal Area Network (PAN). It uses radio waves to transmit data over short distances between devices such as smartphones, laptops, headphones, and smartwatches. Bluetooth technology operates within a limited range, typically up to 30 feet (10 meters), making it ideal for connecting devices within a personal space like a room or a car. Bluetooth-enabled devices communicate with each other by pairing and creating a secure wireless connection, allowing users to transfer data, stream audio, and make hands-free calls. Therefore, out of the given options, Bluetooth is the technology that allows wireless connectivity in a Personal Area Network.

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The first step in editing a chart in MS Excel is to click the chart object. By doing this, you will select the chart and be able to make changes to it, such as resizing, formatting, or adding data. This is the starting point for making any changes to your chart in Excel.

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By default, numeric values in a worksheet are right-aligned. This means that the numbers are positioned towards the right-hand side of their cells, leaving empty space on the left-hand side. This formatting helps make the numbers easier to read and compare, especially when working with columns of data that contain large or small numbers. Other types of data, such as text, are usually left-aligned by default. However, the alignment of data can be easily changed using the formatting options available in the software program used to create and edit the worksheet.

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This question tests core database-modelling terms and cardinality.

(a) Database-management terms.

• (i) Entity: a real-world object, person, place, event or concept about which data is stored in a database (for example a Student, a Book or a Customer). Each entity becomes a table.
• (ii) Attribute: a property or characteristic that describes an entity (for example a Student's name, registration number or date of birth). Attributes form the columns/fields of the table.
• (iii) Relationship: a meaningful association or link between two or more entities (for example a Student "borrows" a Book), showing how their records are connected.

(b)(i) Cardinality. Cardinality describes the number of instances of one entity that can be associated with instances of another entity in a relationship, that is the degree of the relationship between two tables.

(b)(ii) Three cardinality relationships.

• One-to-one (1:1): one record in the first entity relates to exactly one record in the second.
• One-to-many (1:M): one record in the first entity relates to many records in the second.
• Many-to-many (M:N): many records in the first entity relate to many records in the second.

Examination reminder: keep the three terms in order - an entity is the thing, an attribute describes it, and a relationship links entities; cardinality then counts how many on each side (1:1, 1:M, M:N).

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This question tests the application of ICT in different professions. For each friend, state two realistic ICT applications in that specific job.

• Hamza (pilot): uses ICT for computerised flight-navigation and autopilot systems, and for flight simulators used in training; also for radio/radar communication with air-traffic control.
• Emeka (businessman): uses ICT for e-commerce (online buying and selling) and for keeping accounts and records with spreadsheets and databases; also for e-mail and online marketing.
• Funsho (banker): uses ICT for electronic banking such as ATMs and online transfers, and for maintaining customer accounts on a database; also for processing transactions securely.
• Fejiro (manufacturer): uses ICT for computer-controlled/automated production machinery (CAM and robotics) and for computer-aided design (CAD) of products; also for inventory and production control.
• Idongesit (teacher): uses ICT for e-learning and preparing lessons/presentations, and for computer-based setting, marking and record-keeping of results; also for online research.

Examination reminder: tie each ICT use to the actual duties of the profession named; a general answer such as "sends email" earns less than a job-specific one such as "a pilot uses computerised navigation systems".

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This scenario tests the reasons for networking computers and the devices needed to build a network.

(a) Four reasons that motivated connecting the computers.

• To share hardware resources such as printers and scanners among many users.
• To share files and data easily between the computers.
• To enable communication (for example messaging and email) between users.
• To allow centralised management, security and backup, and to share a single Internet connection (also reducing cost).

(b) Four network devices required. A switch (or hub), a router, a network interface card (NIC), and transmission cable such as UTP with connectors (a modem or wireless access point is also acceptable).

(c) One function each of any two of the devices.

• Switch: connects computers within the network and forwards data only to the specific computer it is addressed to.
• Router: connects the network to another network (such as the Internet) and directs data along the best path between networks.
• (NIC: gives a computer its network address and provides the physical connection to the network.)

Examination reminder: distinguish the two connecting devices - a switch links computers within one network, while a router links different networks together.

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This question tests teleconferencing, ATM uses, the modem and transmission means.

(a) Teleconferencing. Teleconferencing is the use of telecommunication and computer technology to hold a meeting or conversation between two or more people in different locations at the same time, using audio and/or video links so they can see and/or hear one another.

(b) Four uses of the Automated Teller Machine (ATM).

• Withdrawing cash.
• Checking account balance.
• Transferring funds between accounts.
• Paying bills / buying airtime (also PIN change and mini statement).

(c)(i) Function of a modem. A modem (modulator-demodulator) converts the computer's digital signals into analog signals for transmission over a communication line (modulation) and converts incoming analog signals back into digital form (demodulation), so that computers can communicate over telephone or similar lines.

(c)(ii) Two means of transmitting information. Through guided/wired media such as cable (twisted-pair, coaxial or fibre-optic) and through unguided/wireless media such as radio waves, microwaves or satellite.

Examination reminder: remember the modem does two opposite jobs - modulation (digital to analog) when sending and demodulation (analog to digital) when receiving.