WAEC SSCE - Computer Studies - 2020

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Computers can be classified based on how they represent data. There are three main types of data representation used in computers: analogue, digital, and hybrid. An analogue computer works by measuring continuously changing physical quantities such as voltage, temperature or pressure. It is able to perform complex mathematical calculations in real-time and is often used for scientific or engineering purposes. A digital computer, on the other hand, represents data using binary digits, or bits, which can be either 0 or 1. It operates using logical operations and is used for a wide range of tasks, from simple calculations to complex simulations and data processing. A hybrid computer combines both analogue and digital components, allowing it to perform both types of operations. It is often used in scientific research, engineering, and medical applications. Therefore, computers can be classified into three types of data representation: analogue, digital, and hybrid.

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Files that contain machine language instructions are called executable files. An executable file is a type of computer file that contains instructions that a computer can directly execute. These instructions are written in a low-level programming language called machine language, which is specific to the computer's processor architecture. When you run an executable file on your computer, the processor reads and executes the instructions contained within the file, carrying out the tasks the program was designed to do. These tasks could be anything from performing a mathematical calculation to displaying a user interface. Executable files are often created by compiling source code files written in higher-level programming languages, such as C or Java. Once the source code has been compiled into machine language, it can be packaged into an executable file that can be run on any computer with a compatible processor architecture.

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The inventions arranged in chronological order are: II. Pascaline (invented in 1642) I. Slide Rule (invented in 1622) IV. Difference Engine (invented in 1822-1834) III. Analytical Engine (designed in the mid-1830s, but not completed) Therefore, the correct order is which is I, IV, III, and II. The slide rule was invented first, followed by the Difference Engine, the Analytical Engine, and finally, the Pascaline.

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Pascal's calculating machine, also known as the Pascaline, was useful in performing addition and subtraction operations. The Pascaline was one of the earliest mechanical calculators, designed by the French mathematician and philosopher Blaise Pascal in the 17th century. It was a simple machine consisting of a series of gears and wheels, which could be used to add and subtract numbers. The user would enter a number by turning the wheels, and then perform the calculation by turning a crank. The result would be displayed in a window on the machine. Although the Pascaline was limited to addition and subtraction, it was a significant development in the history of computing. It paved the way for later calculators and computers, and demonstrated the potential for machines to automate mathematical calculations.

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Bandwidth refers to the transmission capacity of a communication channel. It is the amount of data that can be transferred in a specific amount of time over a network connection. Bandwidth is measured in bits per second (bps), and it determines the speed at which data can be transmitted over a network. The higher the bandwidth, the faster the data can be transmitted. This is important for applications such as video streaming, online gaming, and large file transfers that require a lot of data to be transmitted quickly.

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A pre-designed document coordinating fonts, layout, and background is known as a template. A template is a pre-designed document that provides a framework or structure for creating new documents with a consistent look and feel. It includes a pre-defined layout, fonts, colors, and other design elements that help maintain a consistent style throughout the document. By using a template, you can save time and ensure that your documents have a professional and cohesive appearance. Templates are commonly used in many applications, including word processors, graphic design software, and website builders. For example, in a word processor, you can choose a template for a resume or a business letter that includes pre-defined sections and styles for headings, paragraphs, and fonts. By using a template, you can focus on the content of your document without worrying about the formatting details, and ensure that your document has a professional and polished look.

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In programming, errors can occur during the process of writing and executing a program. These errors can be broadly classified into four types: syntax errors, logic errors, arithmetic errors, and semantic errors. Syntax errors are the most common type of error in programming. They occur when the program violates the rules of the programming language, such as misspelling a keyword or using an incorrect syntax. For example, if a programmer writes "print 'Hello, World!" instead of "print('Hello, World!')", this would be a syntax error. Logic errors occur when the program compiles and executes without errors, but the output is not what was intended. These errors are caused by a flaw in the program's logic or algorithm. For example, if a program is designed to add two numbers but instead subtracts them, this would be a logic error. Arithmetic errors occur when the program tries to perform an illegal or impossible arithmetic operation, such as dividing a number by zero or taking the square root of a negative number. Semantic errors occur when the program compiles and executes without errors, but the output is not what was intended due to a misunderstanding of the requirements or problem. These errors can be difficult to identify and fix since they are not caused by syntax or logic errors, but rather by a flawed understanding of the problem or the user's requirements. In summary, the four types of errors in programming are syntax errors, logic errors, arithmetic errors, and semantic errors. It is important for programmers to be able to identify and fix these errors to ensure that their programs function correctly.

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The option that is not a type of data network is MAC. MAC stands for Media Access Control and is a low-level protocol used to control how data is transmitted over a network. It is not a type of data network, but rather a protocol that is used in various types of networks to manage communication between devices. WAN stands for Wide Area Network and is a type of network that covers a large geographical area, often spanning multiple cities or even countries. MAN stands for Metropolitan Area Network and is a type of network that covers a metropolitan area, such as a city. PAN stands for Personal Area Network and is a type of network that is used for personal devices, such as laptops, smartphones, and tablets, and typically covers a small area, such as a single room or home.

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In graphics, a subscript text refers to a text that is positioned a little bit below a normal line of text. Subscript text is a common formatting technique in graphics and is often used in mathematical or chemical formulas. In these formulas, subscript text is used to indicate the number or quantity of a specific element or molecule. For example, in the chemical formula for water (H2O), the "2" is written as subscript text to indicate that there are two hydrogen atoms in the molecule. Subscript text is positioned below the normal line of text to ensure that it does not interfere with the readability of the main text. It is typically smaller and slightly lower than the normal text, and is often used in conjunction with superscript text, which is positioned slightly above the normal line of text. Together, these formatting techniques allow for clear and concise communication of complex information.

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The proper way to remove a program from a computer is to uninstall it. Uninstalling a program removes all of its files and settings from your computer, freeing up space and ensuring that the program won't interfere with other applications. Deleting a program by just removing its files may leave behind unwanted files and settings that could slow down your computer or cause errors. Archiving a program just means compressing its files into a single file for backup purposes, but it does not remove it from your computer. Disabling a program means stopping it from running temporarily but it does not remove it from your computer. Therefore, the most effective and proper way to remove a program is by uninstalling it.

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The appropriate memory module for graphic design among the options given is S, which is a DIMM memory module with 168 pins. DIMM (Dual In-line Memory Module) memory is faster and has a higher bandwidth compared to other memory types. Graphic design involves working with large image files and multimedia applications that require a lot of memory to operate smoothly. DIMM memory modules have a higher memory capacity, which is suitable for graphic design software that requires a lot of RAM to function efficiently. Therefore, option S with its high capacity and faster speed will be most appropriate for graphic design compared to the other options.

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The feature on the computer desktop that indicates the current active applications is called the task bar. The task bar is typically located at the bottom of the desktop screen and displays icons for all currently running programs, allowing users to easily switch between them by clicking on the respective icon. The task bar may also show other information, such as the time and system notifications. Overall, the task bar provides an easy way for users to keep track of their running applications and switch between them without having to minimize or close other windows.

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The best statement that describes sequential file organization is "Records are sorted according to a key field". In sequential file organization, the records are stored in a sequence one after the other, and are sorted based on a specific field called the key field. This key field is used to arrange the records in a specific order, making it easier to search for and retrieve specific records. The records are stored in the order in which they are added, and can only be accessed in the order in which they are stored. This type of file organization is commonly used in applications that require sequential processing of records, such as batch processing or transactions.

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Handwritten letters, typeset documents or printout characters can be read into the computer by Optical Character Recognition (OCR). OCR is a technology that enables computers to recognize printed or handwritten text characters and convert them into machine-readable digital data. OCR software scans the text characters and uses algorithms to interpret their shapes, patterns, and other features, converting them into an editable format that can be manipulated by computer software. Barcode readers, magnetic ink character recognition, and optical mark readers are all different types of technologies used for reading specific types of data, but they are not designed for recognizing text characters.

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In MS Excel, the average of 10 numbers B1, B2,...,B10 can be calculated by using the formula: = (B1 + B2 + ... + B10)/10 This formula adds up all of the numbers in the range B1:B10 and then divides the sum by 10 to find the average. This formula calculates the arithmetic mean of the given set of numbers. The formula "@SUM(B1:B10)" will only sum the values in the range B1:B10, but will not divide the sum by the number of values to find the average. The formula "#SUM(B1:B10)/10" is not a valid formula in MS Excel. The formula "= B1 +B2 +... + B10/10" is not correct because it divides the sum of the numbers by 10 instead of the count of numbers, which will give an incorrect result. The formula should divide by the count of numbers which is 10 in this case.

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A data bus is a communication system that transfers data between components within a computer. The size of a data bus is determined by the number of bits it can transfer at once. Since the data bus in question can transfer 8 bytes of data at once, it can be rated as a 64-bit data bus. This is because 1 byte is equal to 8 bits, and 8 bytes are equal to 8 * 8 = 64 bits. So, a data bus that is capable of transferring 8 bytes of data at once is a 64-bit data bus.

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If a computer user wants to access the national database from a remote location, they will require a modem, communication software, and a telephone line. A modem is a device that allows the computer to communicate with other computers through a telephone line. Communication software is the program that helps the computer to communicate with other computers and access the national database. A telephone line is the connection between the computer and the telephone network that allows the computer to communicate with other computers. So, in simple terms, the user needs a modem and communication software to send and receive information, and a telephone line to establish the connection.

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The rectangular image consisting of black lines and white spaces that represent data and can be optically read is called a barcode. Barcodes are used to store and retrieve information about products or items quickly and accurately. The pattern of black and white lines in a barcode represents a specific sequence of numbers or letters, which can be read by a barcode scanner. When a barcode is scanned, the scanner translates the pattern of lines and spaces into the corresponding sequence of characters, which can be used to identify the product or item. Barcodes are used in a variety of applications, such as retail sales, inventory management, and shipping and logistics. They are a fast and efficient way to track and manage large numbers of items, and they help to reduce errors and improve accuracy in data entry and tracking. In summary, a barcode is a rectangular image consisting of black lines and white spaces used to represent data that can be optically read by a barcode scanner. It is an important tool for tracking and managing items in a variety of industries.

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Viruses, worms, and trojan horses are all examples of malicious software, also known as malware. Malware is software that is designed to harm or exploit a computer system. A virus is a type of malware that infects a computer file and then spreads to other files on the same computer or to other computers on the same network. A worm is similar to a virus in that it can spread from computer to computer, but it does not need to attach itself to a specific file. Instead, it can create its own network connections to spread. A trojan horse is a type of malware that is disguised as a legitimate software program. When the program is installed, the trojan horse is activated and can then steal sensitive information or cause other harm to the computer system. In summary, viruses, worms, and trojan horses are all malicious software that can harm computer systems, and it is important to protect your computer from these types of threats by using anti-virus software and being cautious when downloading and installing programs.

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The incorrect statement about microcomputers is that "Most micros use rigid disk storage devices rather than floppy disk drives." Microcomputers are also known as personal computers or PCs. They are small, relatively inexpensive computers designed for individual use. The statement that most micros use rigid disk storage devices rather than floppy disk drives is incorrect because most micros actually use floppy disk drives as their primary storage device. Floppy disks are small, portable, and inexpensive storage media that were commonly used in microcomputers for several decades. Rigid disk storage devices, such as hard disk drives, were also used in some microcomputers, but they were not as common as floppy disk drives. Therefore, the correct statement is that microcomputers use floppy disk drives rather than rigid disk storage devices as their primary storage media.

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When you drag and drop an item on the Windows desktop, the item will be moved to a new location. This means that it will be taken from its current place and placed in a new spot on the desktop. The item will no longer be in its original location, but it will still exist and can be accessed from its new spot.

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The correct arrangement of file structure is: II, III, IV, and I. First, we have the smallest unit of data, which is a character (option III). Characters make up fields (option II), which are collections of related characters that form a unit of meaning, such as a person's name or address. Fields then combine to form records (option IV), which are collections of related fields that represent a single entity, such as a customer or an order. Finally, records are grouped together into files (option I), which are collections of related records that are stored together and have a common purpose, such as an employee database or a sales report. Therefore, the correct order is: II (character), III (field), IV (record), and I (file).

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The field length determines the maximum number of characters the field can accommodate. This means that when you create a database field, you can specify the maximum number of characters (e.g. letters, numbers, symbols) that can be stored in that field. This helps to ensure that the data stored in the field is consistent and can be easily managed. For example, if you have a field for storing email addresses, you might specify a field length of 50 characters to accommodate the longest email address you expect to store.

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An analogue camera is the only device from the options that will not require the use of system software to operate. Analogue cameras use physical mechanisms to capture and store images, without the use of digital technology or software. On the other hand, MICR, mobile phones, and OCR all use digital technology and therefore require system software to operate. MICR is a technology used for processing and storing financial transactions, while OCR stands for Optical Character Recognition, which uses software to convert scanned images of text into machine-readable text. Mobile phones also use software to run various applications and perform tasks.

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The rectangular image that consists of black lines and white spaces representing data that can be optically read is called a barcode. Barcodes are widely used in various industries and businesses to automate the process of identifying and tracking products, inventory, and other data. The black lines and white spaces in a barcode represent a specific code or information that can be read by a barcode scanner or reader. When the scanner reads the barcode, it translates the code into a digital signal that can be processed by a computer or other devices. This makes barcodes a simple and efficient way to store and retrieve information.

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Without seeing Figure 1, it is not possible to determine the value of Z when X = 1 and Y = 0. Please provide a visual representation of Figure 1 or a detailed description of the variables and equations used in the figure for me to help you determine the value of Z.

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An algorithm can be described as a sequence of instructions for solving a problem. In simple terms, an algorithm is a set of instructions that a computer or a person can follow to complete a specific task or solve a problem. It is a step-by-step process that outlines the exact order in which certain operations should be performed to achieve a particular result. Algorithms are used in a wide range of applications, from solving mathematical problems to sorting data to building complex systems. For example, an algorithm for sorting a list of numbers might involve comparing each pair of numbers in the list and swapping them if they are not in the correct order, and then repeating this process until the entire list is sorted. The key aspect of an algorithm is that it provides a clear and unambiguous set of instructions that can be followed to achieve the desired outcome.

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A database management system (DBMS) is a software system that allows users to store, organize, and manage data in a database. It performs several functions to ensure that the data is accurate, consistent, and secure. Among the functions of a DBMS are backup and replication, operation, rule enforcement, and security. However, the question asks which of these functions is NOT performed by a DBMS. Therefore, the correct answer is one of these functions that is NOT performed by a DBMS. The function that is NOT performed by a DBMS is "backup and replication." Backup and replication are actually performed by a DBMS, and they are essential for ensuring that data is not lost due to system failures or disasters. Operation is another function of a DBMS, which includes tasks such as inserting, updating, and deleting data from a database. Rule enforcement is another function that ensures that data is consistent and conforms to specific standards or rules. Finally, security is a critical function of a DBMS, which includes features like access control, authentication, and encryption to protect data from unauthorized access or tampering. In summary, all the listed functions, including backup and replication, are performed by a DBMS, so the correct answer is "None of the above."

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Out of the given options, Fox Pro is the most suitable application package for database management. Fox Pro is a relational database management system that allows users to create, manage, and manipulate databases. It provides powerful tools for data entry, data validation, and data analysis. It is widely used for creating database applications in various industries such as finance, manufacturing, and healthcare. On the other hand, Photoshop is a software package used for image editing and manipulation. MS Publisher is a desktop publishing application used for creating documents such as newsletters, brochures, and flyers. Macromedia Flash is a multimedia authoring tool used for creating interactive applications such as animations, games, and videos. None of these applications are designed for managing databases. Therefore, if you are looking for an application package to manage your databases, Fox Pro is the most appropriate option.

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The communication of knowledge, concepts, and ideas is referred to as "information transmission." Information transmission refers to the process of transmitting or transferring information from one place to another, or from one person to another. It can be done through various means, such as speaking, writing, broadcasting, or using digital devices. The goal of information transmission is to effectively convey a message so that it is understood by the recipient. So, the term used to describe the communication of knowledge, concepts, and ideas is information transmission.

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The memory types that are nonvolatile are I and III, PROM and EEPROM. Nonvolatile memory is a type of memory that retains its stored data even when the power is turned off. PROM (Programmable Read-Only Memory) is a type of nonvolatile memory that can only be written to once and then its contents are permanently fixed. EEPROM (Electrically Erasable Programmable Read-Only Memory) is similar to PROM, but allows for the data to be erased and rewritten multiple times. SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory) are types of volatile memory, which means that they lose their stored data when the power is turned off. So, the nonvolatile memory types are PROM and EEPROM.

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(a) A home page is the main or starting page of a website that provides an overview of the website's content and navigation options. It serves as a gateway to access different sections of the website and contains links to other pages.

(b)(i) Two reasons why computers are connected include:

1. Communication: Computers are connected to each other to enable communication between users. With the help of the internet, users can exchange messages, share files, and collaborate on projects.
2. Resource sharing: Computers can be connected to share resources such as printers, scanners, and external hard drives. This enables users to access resources from other computers on the network and reduces the need for duplicate equipment.

(ii) Two reasons why computers are not connected include:

1. Security concerns: In some cases, computers may not be connected to prevent unauthorized access to sensitive data. This is particularly important in organizations that deal with confidential information, such as financial institutions and government agencies.
2. Isolation: Computers may not be connected if they are used for specialized tasks that do not require network access, such as controlling manufacturing equipment or performing scientific simulations.

(c) Four additional items needed to send an email include:

1. Email address of the recipient: To send an email, you need to know the email address of the person or people you want to send the email to. This is the unique identifier that tells the email system where to send the message.
2. Email address of the sender: You also need to provide your own email address so that the recipient can reply to your message.
3. Subject line: The subject line is a brief description of the email's content and helps the recipient understand what the email is about.
4. Message body: The message body is the main content of the email and can include text, images, and attachments. It is where you communicate your message to the recipient.

To send an email, you typically compose a new message in your email client, enter the recipient's email address, fill in the subject line and message body, and click send. The email system then routes the message to the recipient's email server, where it can be accessed using their email client.

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(a)
DEVICE | NAME OF INVENTOR
--- | ---
Analytical Engine | Charles Babbage
Mechanical Digital Calculator | Blaise Pascal
Slide Rule | William Oughtred
Punched Card | Herman Hollerith

(b)
(i) Input devices are hardware devices that allow users to input data or instructions into a computer system for processing. These devices convert user input into digital signals that can be processed by the computer.
(ii) Four examples of input devices are:
1. Keyboard: This is the most common input device, which allows users to type text and commands into a computer system.
2. Mouse: A mouse is a pointing device that allows users to move a cursor on the screen and select options by clicking buttons.
3. Scanner: A scanner is an input device that allows users to digitize printed images or documents by scanning them into the computer system.
4. Microphone: A microphone is an input device that allows users to record and input audio data into the computer system.

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(a)

1. Representation: An algorithm is a step-by-step procedure for solving a problem, whereas a flowchart is a graphical representation of an algorithm that uses symbols to depict different operations.
2. Detail level: An algorithm is typically written in a programming language and provides a higher level of detail in terms of the logic and syntax required for the program to run, while a flowchart is a visual representation that provides a broad overview of the steps involved in the algorithm.

(b)

1. Disk cleanup: A utility program that frees up disk space by removing temporary files, internet cache files, and other unnecessary files from your computer.
2. Antivirus software: A utility program that protects your computer from viruses, malware, and other malicious software.
3. Compression software: A utility program that compresses and decompresses files and folders to save disk space and make it easier to transfer large files.

(c)

A flowchart for updating a customer's balance could involve the following steps:

1. Start the program.
2. Ask the user for the customer's name.
3. Retrieve the customer's balance from a database.
4. Ask the user for the amount to be added to the balance.
5. Add the amount to the customer's balance.
6. Update the customer's balance in the database.
7. Display the updated balance to the user.
8. End the program.

This flowchart outlines a simple process for updating a customer's balance. It begins by asking the user for the customer's name, retrieves the current balance from a database, and prompts the user for the amount to be added. The program then adds the amount to the current balance, updates the balance in the database, and displays the updated balance to the user before ending the program.

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(a)

(i) Video conferencing is a technology that allows two or more people in different locations to communicate and interact in real-time using video and audio transmission over the internet or a network.

(ii) Four essential items to a video conference include:

1. Video camera: A device that captures and transmits video images of the participants to other locations.
2. Microphone: A device that captures and transmits audio sounds to other locations.
3. Display screen: A device that displays the video images and audio of the other participants to the viewer.
4. Speaker: A device that plays the audio sound of the other participants to the viewer.

(III) Two examples of other hardware components essential to a video conference are:

1. Codec: A device or software that compresses and decompresses video and audio data for transmission over the internet or a network.
2. Network switch: A device that connects multiple devices on a network and manages the flow of data between them.

(b) Two examples of data cables are:

1. Ethernet cable: A type of cable used to connect devices to a network, such as a router or a switch. It is also used for high-speed internet connections.
2. USB cable: A type of cable used to connect devices, such as a computer or a printer, to transfer data or to charge the device.

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a) Two graphic applications used in editing photographs are Adobe Photoshop and GIMP (GNU Image Manipulation Program).

b) Four steps to insert the edited photographs into a multimedia application are:
1. Save the edited photograph in a compatible file format, such as JPEG, PNG, or TIFF.
2. Open the multimedia application where you want to insert the photograph, such as Microsoft PowerPoint or Adobe Premiere Pro.
3. Navigate to the location where the edited photograph is saved on your computer.
4. Drag and drop the photograph into the multimedia application, or use the insert image command to place it into the desired location.

c) One multimedia element that could be included in a presentation other than graphics and texts is audio. Audio elements, such as music, sound effects, or voiceovers, can enhance a presentation and make it more engaging for the audience.

d) Three multimedia hardware for developing and displaying presentations are:
1. Computer: A computer is necessary for creating and editing multimedia presentations. It is also used for displaying the final presentation to the audience.
2. Projector: A projector is used to display the presentation on a larger screen or surface, such as a wall or screen. It connects to the computer and displays the output of the presentation software.
3. Speakers: Speakers are necessary for playing audio elements in the presentation. They can be built into the computer or projector, or external speakers can be connected to enhance the audio quality.