WAEC SSCE - Computer Studies - 2021

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A computer system on the network that stores web pages, takes requests from clients, and sends out information is called a "web server". A web server is a program or a computer that stores, processes, and delivers web pages to clients on request. When a user enters a website's URL into a web browser, the browser sends a request to the web server asking for the website's content. The web server then responds by sending the requested web pages and files to the user's web browser, which displays them on the screen. Web servers use protocols like HTTP (Hypertext Transfer Protocol) to communicate with clients and deliver web pages. Examples of web servers include Apache, Nginx, and Microsoft IIS.

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The logic gates represented in Figure 1 are called NAND gates. A NAND gate is a digital logic gate that gives an output of "low" (logic 0) only when all of its inputs are "high" (logic 1). In all other cases, the output of a NAND gate is "high" (logic 1). In Figure 1, there are two inputs connected to a NAND gate symbol (which looks like an AND gate with a small circle at the output). This indicates that the gate performs the NAND function on its inputs.

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The use of natural language and symbols to write instructions for the computer is called "high level language programming". High level programming languages use human-readable instructions and structures to write programs that can be understood by both humans and computers. Examples of high level programming languages include Python, Java, and C++. In contrast, machine language programming and assembly language programming use low level instructions and binary code that are difficult for humans to read and understand. Algorithm language programming is not a commonly used term in programming and may refer to the use of algorithms in programming, rather than a specific language.

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The statement that is true about URL is that it is "the address of a document or 'page' on the World Wide Web". URL stands for Uniform Resource Locator and it is a reference to the web resource that specifies its location on the internet. In simpler terms, a URL is the web address of a specific page or document on the internet. URLs consist of several parts, including the protocol (such as http or https), the domain name or IP address of the server where the resource is located, and the path to the specific file or document. The other options are not true about URL. A URL is not a computer software program, a type of web server, or an acronym for unlimited resources for learning.

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The condition "If C = 10, stop picking orange" is not true based on the flowchart in Figure 4. If N is represented by 10, then when C is equal to 10, the flowchart shows that the next step is to "continue picking orange", not to "stop picking orange".

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A single character in an EBCDIC encoding system is represented using 8 bits. This means that each character is represented by a unique combination of 8 binary digits, or bits. 8 bits provides enough combinations to represent a wide range of characters, including letters, numbers, and special symbols. This allows EBCDIC to support a variety of character sets and languages, making it a flexible and widely-used encoding system.

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The windows shortcut key for closing an active application is Alt+F4. When you press the Alt+F4 keys on your keyboard, it sends a signal to the currently active application that you want to close it. This can be useful when you want to quickly exit a program that you are no longer using. The Alt+F4 shortcut is designed to work with most applications in Windows, including web browsers, text editors, and media players. When you press Alt+F4, the program will usually ask if you want to save any changes you've made before closing. It's important to note that Alt+F4 will only close the active application, which means that if you have multiple programs open, you'll need to switch to each one and press Alt+F4 individually to close them. In summary, Alt+F4 is a simple and convenient shortcut key that can help you quickly close applications in Windows.

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The cell in MS Excel that contains the pointer or cursor is called the "Active Cell". An active cell is the cell that is currently selected and ready to accept input. It is the cell in which you can type or edit data. The active cell is surrounded by a border and is the cell that is currently in use in the worksheet. This makes it easy to identify and is the cell that will be affected by any actions you take in the worksheet.

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Field engineers are professionals who perform their work outside the office or in the field. When it comes to choosing a computer, factors such as cost, size, convenience, and battery life are essential to consider. Among the given options, the factors that will most likely motivate a field engineer to choose a notebook computer over a desktop computer are size, convenience, and battery life. Size: A notebook computer is more portable and lightweight compared to a desktop computer. It can easily fit into a bag or backpack, making it easy to transport from one location to another. This is essential for field engineers who need to move around to different job sites. Convenience: A notebook computer is also more convenient than a desktop computer because it does not require a power outlet to function. A field engineer can use the notebook computer on the go without worrying about finding a power source. Additionally, a notebook computer allows for more flexibility when it comes to where work can be done, as it can be used in a car or at a remote job site. Battery life: A notebook computer's battery life is an important factor for field engineers who may not have access to a power source for an extended period. A notebook computer with a long battery life allows field engineers to work for extended periods without needing to recharge the device. Cost is also an important consideration for any professional, including field engineers. However, the convenience and portability of a notebook computer make it a more attractive option for field engineers who need to work on the go. Overall, the factors that are most likely to motivate a field engineer to choose a notebook computer over a desktop computer are size, convenience, and battery life.

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To transfer a 10 GB file, you need to find out how many 750 MB CD-ROM discs you would need. Each CD-ROM has a capacity of 750 MB, so you need to divide 10 GB by 750 MB to find out the number of discs required. 10 GB / 750 MB = 13.333 Since you can't have a fraction of a CD, you would need to round up to the nearest whole number. Therefore, you would need 14 CD-ROM discs to transfer a 10 GB file.

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The type of relationship that can be deduced from the statement "a department has many employees" is a "one-to-many" relationship. In a one-to-many relationship, one entity in a database is related to many instances of another entity. In this case, the "department" entity is related to many instances of the "employee" entity. This means that a single department can have multiple employees working for it, but each employee can only be associated with one department at a time. For example, in a database that tracks employee information for a company, there might be a "departments" table and an "employees" table. The "departments" table would contain information about each department in the company, such as the department name and manager, while the "employees" table would contain information about each employee, such as their name, job title, and department ID. The department ID field in the "employees" table would be used to establish the one-to-many relationship between the "departments" and "employees" tables. Each employee record would have a department ID that corresponds to a department record in the "departments" table, allowing the database to link employees to their respective departments. Overall, the one-to-many relationship between departments and employees is a common type of relationship in many database systems, and is useful for organizing and managing large amounts of related data.

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The correct answer is either "analogue" or "digital," depending on the type of signal being transmitted. Analog signals are continuous, meaning they can take on any value within a range of values, whereas digital signals are discrete, meaning they can only take on specific, predetermined values. Without more information or context about the specific signals being transmitted in Figure 6, it is impossible to determine whether the signals are analogue or digital. However, it is safe to assume that they are one of these two types, as these are the most common types of signals used for communication between modems. In summary, the answer to the question "In Figure 6 the signals from modem X to modem Y is?" is either "analogue" or "digital," depending on the type of signal being transmitted.

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The sequence of operation of a computer is as follows: 1. Input: The computer accepts data or information from input devices such as a keyboard, mouse, microphone, or scanner. 2. Processing: The computer processes the input data by performing operations on it using its central processing unit (CPU), memory, and other components. The processing involves performing arithmetic and logical operations on the data, manipulating it, and storing it in memory. 3. Output: After processing the data, the computer produces output in the form of information or results. The output can be displayed on a screen, printed on paper, or sent to other devices such as a speaker or a network. In summary, the sequence of operation of a computer involves accepting input data, processing it using the CPU and memory, and producing output in the form of information or results.

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The correct answer is "customization." Customization refers to the process of changing the default settings or appearance of the Taskbar in Windows by a user. This can include changing the position of the Taskbar, resizing it, changing its color or transparency, and adding or removing icons. Customizing the Taskbar allows users to personalize their computing experience and make their workflow more efficient by tailoring the Taskbar to their specific needs and preferences.

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Data created by the user is called primary data. This refers to information that is collected directly by the person or organization that needs it, typically through surveys, experiments, or observations. Primary data is unique to the specific research question or problem and is tailored to meet the specific needs of the user. It is usually more accurate and reliable than secondary data, which is data that has been collected and reported by someone else for another purpose. Examples of primary data include customer feedback surveys, laboratory experiments, and field observations.

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The part of the computer system shown in Figure 11 is used to power on or off the computer. The figure shows a power button symbol, which is typically used to turn on or off the computer. When you press the power button, the computer's power supply sends electricity to the motherboard, which then initializes the various components in the computer and starts up the operating system. Pressing and holding the power button for a few seconds can force the computer to shut down in case it's not responding or has frozen. Therefore, the power button is an essential component of any computer system, allowing users to turn it on and off as needed.

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The option that is not a similarity between a computer file and manual file is "store multimedia." Both computer files and manual files can be accessed and retrieved to obtain the information contained within them. A manual file might refer to a physical document or record, while a computer file is a digital representation of data stored on a computer system, but in both cases, the information can be retrieved and accessed. Both types of files can contain information, such as text, numbers, or images. However, manual files may be limited in the type of information they can store, as they are physical documents, while computer files can store a wide range of information, including multimedia like videos, audio, and animations. Therefore, while both types of files share similarities in terms of accessibility, retrieval, and information storage, the ability to store multimedia is a feature that is unique to computer files.

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A collection of wires through which data are transmitted from one part of the computer to another is known as a bus. A bus is a set of wires that transfer data and information between different components in a computer. It acts like a highway for data to travel from one place to another within the computer. In simple terms, a bus is like a pathway that allows different parts of the computer to communicate and exchange information with each other.

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The statement "data is unorganized" is not true. Data can be either organized or unorganized. Data refers to a collection of raw facts and figures that have not been processed or analyzed. However, this data can be organized into a more meaningful format, such as tables, charts, or graphs, that can make it easier to understand and analyze. Once data is organized and analyzed, it can be converted into information, which is used for decision making. Therefore, all the other descriptions are true: data can be converted to information, it is a collection of raw facts and figures, and it is used for decision making.

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The part of the MS Word interface labelled II in Figure 10 is called "Print Layout". This option allows users to view their document as it would appear on a printed page. It shows page margins, page breaks, headers and footers, and other elements that are important for formatting a printed document. Users can use this view to make sure their document looks the way they want it to before printing.

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Quantitative data can exist in both continuous and discrete forms. Continuous data can take on any value within a range, such as height or weight, and is typically measured using a scale. Discrete data, on the other hand, can only take on specific values, such as the number of children in a family or the number of pets someone has. Both forms of data can be used to perform mathematical operations and statistical analyses, and can provide valuable insights into a wide range of phenomena. For example, quantitative data can be used to study trends in population growth, track changes in consumer behavior, or explore the relationship between variables in scientific research.

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Spyware is specifically designed to covertly collect information about a person or organization without their knowledge or consent. Unlike adware, which displays advertisements, a time bomb, which is a type of malware that is set to execute at a specific time, or a trojan horse, which disguises itself as a legitimate program but carries out harmful actions, spyware focuses on gathering sensitive information such as browsing habits, keystrokes, personal data, and other confidential information. This information is then typically transmitted to third parties without the user's consent, posing significant privacy and security risks. Therefore, spyware fits the description of a computer program that gathers information without the user's knowledge or consent, making it the correct choice for the given question.

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The part of the graphic interface labelled V in Figure 8 is called "fit to window". This option allows you to automatically adjust the size of the image or graphic to fit within the boundaries of the window or screen. For example, if you have an image that is too large to be displayed on your screen without scrolling or resizing, you can select the "fit to window" option and the image will be automatically scaled down to fit within the dimensions of the window or screen. This can be a helpful feature for working with large images or graphics, as it allows you to view them in their entirety without having to scroll or zoom in and out manually.

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The operation of a computer and its peripherals is controlled by the system software. System software, also known as the operating system, is the software that manages and controls the computer hardware and other software programs. It acts as a bridge between the computer hardware and the user, allowing the user to interact with the computer and run different applications. Examples of popular operating systems are Windows, MacOS, and Linux. The operating system manages the computer's memory, processing power, and input/output operations, ensuring that all components work together smoothly and efficiently.

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Virus infections can cause various harmful effects on a computer system, but among the given options, the action that is not an effect of virus infection is hard disk failure. A virus is a malicious software program that can infect a computer system, replicate itself and spread to other systems. Once a virus infects a system, it can cause various problems such as deleting files, slowing down the system's operation, and displaying unwanted messages. Deletion of files: A virus can delete important files or programs on a system, making it difficult or impossible to use certain applications or access certain data. Slow operation: A virus can consume a significant amount of a system's resources, which can cause the computer to operate slowly and inefficiently. This can cause frustration and hinder productivity. Display of unwanted messages: A virus can display pop-up messages or advertisements that are unwanted and can be distracting or harmful. These messages may also try to trick the user into downloading more harmful software. Hard disk failure: While a virus can cause data loss and corruption, it is not typically the direct cause of hard disk failure. Hard disk failure is usually due to physical damage or wear and tear over time. In summary, a virus infection can cause several negative effects on a computer system, including file deletion, slow operation, and display of unwanted messages. However, hard disk failure is not typically caused by a virus.

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To prevent data loss, a user must backup the data. This means making a copy of important files and storing them in a safe place, such as an external hard drive or cloud storage. This way, if the original data gets lost or damaged, the user still has a copy that they can use to restore the data.

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COBOL (Common Business Oriented Language) was developed specifically for business operations. It was created in the late 1950s and early 1960s, during a time when computers were becoming more prevalent in the business world. COBOL was designed to handle large amounts of data, particularly data related to business transactions and financial records. It was intended to be an easy-to-learn language that could be used by non-technical people, such as business analysts and accountants, to write computer programs. Today, COBOL is still used by many organizations for legacy systems that were developed using the language.

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The figure 2 in the number 1101\(_2\) is indicated in MS Word using the superscript feature. The superscript feature in MS Word is used to format text or numbers in a smaller font size and raised above the normal line of text. In this case, the superscript feature can be used to raise the number 2 above the rest of the binary number 1101, indicating its position as the second power or exponent of the base number 2. Therefore, to indicate the number 2 in the binary number 1101\(_2\) using MS Word, you can type "1101^2" where the superscript feature is used to raise the number 2. The resulting output will be "1101²" with the 2 raised and in a smaller font size.

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The logic circuit in Figure 3 has two inputs, A and B, and one input C. The output is Z. Looking at the circuit, we can see that the input C is connected directly to the output Z. This means that the value of C will always be present in the output Z, regardless of the values of A and B. The two inputs A and B are connected to an OR gate, and the output of the OR gate is connected to a NOT gate. The NOT gate inverts the output of the OR gate, which means that if the OR gate output is 0 (i.e., A and B are both 0), then the NOT gate output will be 1. Conversely, if the OR gate output is 1 (i.e., at least one of A or B is 1), then the NOT gate output will be 0. So, the overall logic equation for the circuit is: Z = \(\overline{A+B}\) \(\overline{C}\) In other words, the output Z is the logical NOT of the OR of A and B, ANDed with the logical NOT of C.

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The operating system does not perform the operation of "creation of data". This operation is typically performed by the user or other software programs running on the system. The operating system's role is to manage and organize the data and resources of the computer, but it does not create new data.

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The statement that is true about supercomputers is that they can process billions of operations in a second. Supercomputers are designed to perform complex and sophisticated computations that are beyond the capabilities of regular computers. They are capable of processing enormous amounts of data and performing multiple calculations simultaneously, which allows them to solve complex problems that regular computers cannot. However, they are typically large, expensive machines that are used in specialized fields such as scientific research, engineering, and weather forecasting, among others. They are not commonly found in homes and offices due to their high cost and specialized nature.

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(a) What are "Reports" in a database system?

A report is a database object used to organise, summarise and present data from one or more tables or queries in a formatted, printable layout. Reports are designed mainly for output: they allow the user to arrange records neatly, group and sort them, perform calculations such as totals and averages, and produce professional printed documents such as invoices, result sheets or mailing lists.

(b) Four ways in which reports can be viewed in a database management system (MS Access):

1. Report View - shows the finished report on screen as a continuous view.
2. Print Preview - shows exactly how the report will look when printed, page by page.
3. Layout View - shows the report with live data while allowing you to adjust the design and column widths.
4. Design View - shows the underlying structure (sections such as header, detail and footer) for detailed editing of the report.

(c) Steps to print a report in MS Access:

1. Open the database and, in the Navigation Pane, locate and open (or select) the report you want to print.
2. Switch to Print Preview to confirm the layout, page size and orientation are correct.
3. Click the File tab (or the Office/Backstage button) and choose Print.
4. In the Print dialog box, select the correct printer and set the options (number of copies, page range).
5. Click OK (or Print) to send the report to the printer, then collect the printout.

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(a) Convert \(AB1_{16}\) to the Octal system

Step 1: Write each hexadecimal digit as 4 binary bits.

\[A=1010,\quad B=1011,\quad 1=0001\]

\[AB1_{16}=1010\,1011\,0001_2\]

Step 2: Regroup the binary digits in threes from the right.

\[101\;010\;110\;001\]

Step 3: Convert each group of three to its octal digit.

\[101=5,\;010=2,\;110=6,\;001=1\]

\[\therefore AB1_{16}=5261_8\]

(b) Convert \(1110111.101_2\) to the Denary (base 10) system

Integer part, using place values \(64,32,16,8,4,2,1\):

\[1110111_2=64+32+16+0+4+2+1=119\]

Fractional part, using place values \(\tfrac{1}{2},\tfrac{1}{4},\tfrac{1}{8}\):

\[.101_2=1(0.5)+0(0.25)+1(0.125)=0.625\]

\[\therefore 1110111.101_2=119.625_{10}\]

(c) Convert \(507_8\) to the Binary system

Since the digit 7 is not valid in base 2, the number is in the octal system. Write each octal digit as 3 binary bits.

\[5=101,\quad 0=000,\quad 7=111\]

\[\therefore 507_8=101\,000\,111_2=101000111_2\]

Check by way of denary: \(507_8=5\times8^2+0\times8^1+7\times8^0=320+0+7=327_{10}\), and repeated division of \(327\) by 2 gives \(101000111_2\), confirming the result.