WAEC SSCE - Computer Studies - 2015

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A high level language can be converted to a machine language using a "compiler". A compiler is a software program that translates the code written in a high-level programming language such as Java, C++, or Python, into machine code that the computer can understand. The process of converting high-level code to machine code involves several steps, including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation. The compiler takes the source code written in a high-level language and converts it into an executable program in machine code, which can be run on a computer. An editor is a software program used for creating and editing text files, but it does not have the capability to convert high-level code to machine code. A utility program is a general term used to describe any program that performs a specific task, but it is not specifically designed to convert high-level code to machine code. An operating system is the software that manages the hardware and software resources of a computer, but it does not perform the task of converting high-level code to machine code. In summary, a compiler is the software program that can convert high-level code to machine code, which is necessary for a computer to execute the program.

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The keyboard command used to copy text in a MS-Word document is Ctrl + C. Ctrl + C is a keyboard shortcut used to copy selected text or object to the clipboard in many computer programs, including MS-Word. After selecting the text that you want to copy, you can use this shortcut to copy the text to the clipboard. Once the text is copied to the clipboard, you can use the Ctrl + V shortcut to paste the text into another location in the same document or into a different document or application. Therefore, the correct answer is Ctrl + C.

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If the output signal of any logic gate is fed into an inverter, the result is the inverse of the output signal. An inverter is a logic gate that has one input and one output. It changes the logic state of the input signal to its complementary state at the output. If the input signal is a logic 1, the output signal is a logic 0, and if the input signal is a logic 0, the output signal is a logic 1. When the output signal of any logic gate is fed into an inverter, the logic state of the signal is inverted, which means that the output signal of the inverter will be the opposite of the output signal of the logic gate. Therefore, the result of feeding the output signal of any logic gate into an inverter is the inverse of the output signal.

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The shortcut command used in restarting a computer is Alt+Ctrl+Del. Alt+Ctrl+Del is a keyboard shortcut that is commonly used in Microsoft Windows operating systems to bring up a menu that allows the user to log out, lock the computer, switch to another user, open Task Manager or shut down or restart the computer. The menu that appears after pressing Alt+Ctrl+Del varies depending on the version of the operating system and the settings of the computer. However, one of the options that typically appears on this menu is the option to restart the computer. Therefore, the correct answer is Alt+Ctrl+Del.

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Data loss in a computer cannot be prevented by the use of a password. A password is a security measure that restricts access to a computer or its files, but it cannot prevent data loss due to hardware failure, software bugs, accidental deletion, or other factors that can corrupt or delete data. To prevent data loss, it is essential to have a backup system in place. A backup is a copy of important data that can be restored in case the original data is lost, damaged, or corrupted. A flash drive can be used as a backup storage device, but it is not a reliable backup solution as it can also fail or get lost. An antivirus program can protect a computer from viruses, malware, and other online threats, but it cannot prevent data loss due to hardware or software issues. Therefore, to prevent data loss, it is important to have a backup system in place and regularly back up important data.

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The network device that is not a network device is "Port". A port is not a network device; it is a connection point or a socket on a network device such as a switch, hub, or router. A hub is a network device that connects multiple devices together to form a network, and it is responsible for transmitting data to all the devices connected to it. A modem is a device that connects a computer or network to the internet or other wide-area networks by converting digital signals into analog signals that can be transmitted over telephone lines or cable lines. A router is a network device that forwards data packets between computer networks, allowing devices on different networks to communicate with each other. It determines the best path for data transmission and ensures that data is sent to the correct destination. In summary, a port is not a network device, but a connection point on a network device that allows devices to communicate with each other.

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A pictorial representation of program flow is called a flow chart. A flow chart is a diagrammatic representation of an algorithm or process. It uses different shapes and symbols to illustrate the different steps involved in the process, and it shows the logical sequence in which those steps occur. Flow charts are commonly used in computer programming to represent program logic, as they provide a clear and concise visual representation of the steps involved in a process or algorithm. They can be used to design, analyze, and document processes and algorithms, making them an important tool in software development and other areas of computer science.

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In a network, a workstation is usually connected to a switch. A switch is a networking device that connects devices on a local area network (LAN) by using packet switching to forward and filter data to its destination. A switch is typically used to connect multiple devices together, such as computers, printers, and servers, in order to allow them to communicate with each other and share resources. When a workstation is connected to a switch, it can send and receive data to and from other devices on the same network. The switch helps to manage the flow of traffic on the network by directing data only to the intended recipient device, rather than broadcasting it to all devices on the network, which can reduce network congestion and improve performance. While a hub, modem, and router can also be used to connect devices to a network, a switch is the most common device used in modern networks due to its efficiency and ability to handle large amounts of network traffic. In summary, a workstation is usually connected to a switch in a network, which allows it to communicate with other devices on the same network and share resources.

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The computer memory is measured in "bytes". A byte is a unit of digital information that consists of eight bits. Each bit can represent either a 0 or a 1, and combinations of bits can be used to represent larger values, such as letters, numbers, and symbols. Computer memory, also known as RAM (Random Access Memory), is a type of volatile memory that is used to temporarily store data that the computer is currently processing. The amount of memory a computer has can affect its performance, as more memory allows the computer to store and process more data at once. Hertz is a unit of measurement for frequency, and nibble is a unit of measurement for data that consists of four bits. Therefore, neither of these units of measurement is used to measure computer memory. In summary, the computer memory is measured in bytes, which is a unit of digital information that consists of eight bits.

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The main advantage of intellectual property rights is the encouragement of innovations. Intellectual property rights grant legal protections and exclusive rights to the creators of new ideas, inventions, or artistic works, allowing them to profit from their creations and have control over their use. This encourages individuals and businesses to invest in research and development, as they know that they will have legal protection for their intellectual property, which can lead to the creation of new products and technologies that benefit society as a whole. Without intellectual property rights, there would be little incentive for individuals and businesses to invest in innovation, as they would not be able to reap the benefits of their creations.

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The statement that is true of free software is that it is a licensed software with permission to copy freely. Free software refers to software that is distributed with a license that allows users to use, study, modify, and distribute the software without any restrictions. This means that users are free to copy, modify, and distribute the software to anyone they want without having to pay any licensing fees. However, the software is still licensed, and users must comply with the terms and conditions of the license agreement when using the software. Therefore, the correct option is that free software is a licensed software with permission to copy freely.

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The operating system, translators, and utility programs are examples of system software. System software is a type of software that is designed to manage and control the hardware and software resources of a computer system. It provides a platform for the execution of other software and applications. The operating system is the most important example of system software because it manages the resources of the computer system, such as the processor, memory, and storage, and provides a user interface to interact with the computer. Translators are programs that convert code written in one programming language into another programming language or machine language. They are essential tools for software development. Utility programs are a type of system software that performs specific tasks to optimize or maintain the performance of the computer system. Examples of utility programs include antivirus software, disk defragmenters, and backup software. Overall, system software is critical to the functioning of a computer system, and it is distinct from application software, which is designed to perform specific tasks for the user.

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A possible reason for the message "page not found" when browsing on the internet is that a connection between the client (the user's computer or device) and the server hosting the website has been lost. When a user types in a website address or clicks on a link, their web browser sends a request to the server hosting the website to send back the web page. If the server is not responding or there is a problem with the internet connection, the web browser may display a message such as "page not found" or "404 error". This can occur for a variety of reasons, including temporary internet connectivity issues, server downtime, or website maintenance. In some cases, the website may have been removed or the address may have been changed, resulting in the page no longer being available. In contrast, the weather conditions or speed of the web browser are not factors that typically affect the ability to access a web page. Multiple web pages loading at the same time may slow down the browsing experience, but it is unlikely to result in a "page not found" error. In summary, a possible reason for the message "page not found" when browsing on the internet is that a connection between the client and server has been lost or there is an issue with the server hosting the website.

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The term "bus width" in data transfer refers to the number of wires in the bus that carry information to the processor at a time. In computing, a bus is a communication system that transfers data between different components inside a computer or between computers. The bus width determines how many bits of information can be transferred at once. It is usually measured in bits or bytes. For example, a computer with a 32-bit bus can transfer 32 bits of data at once. This means that it can transfer data faster than a computer with a 16-bit bus. Therefore, the correct option is "number of wires in the bus that carry information to the processor at a time".

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To convert a number from base 10 to base 8, we need to divide the number by 8 and keep track of the remainder at each step until the quotient becomes 0. Let's start with the number 9 in base 10. If we divide 9 by 8, the quotient is 1 and the remainder is 1. So, we can write 9 in base 8 as 11, where the first digit represents the quotient and the second digit represents the remainder. Therefore, X is 1, and the answer is 11.

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The item that changes shape depending on the task being performed is the Mouse pointer. The mouse pointer is a small arrow-shaped icon that moves on the computer screen when the mouse is moved. It is used to select, click, drag and interact with different elements on the screen. Depending on the task being performed, the mouse pointer may change its shape to indicate a different action or state. For example, it may change to a hand icon when hovering over a link or button, a text cursor when hovering over a text field, or a resizing arrow when hovering over the edge of a window or object. Therefore, the correct answer is the Mouse pointer.

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The most efficient way to move the second paragraph and place it after the fourth paragraph in word processing is to use the cut and paste function. First, highlight the entire second paragraph, then select the "cut" function to remove the paragraph from its original position. Next, place the cursor at the beginning of the fourth paragraph and select the "paste" function. This will insert the second paragraph immediately after the fourth paragraph. Using the cut and paste function is faster than copying and pasting because it eliminates the need to delete the original paragraph.

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Yes, the computer hardware is made up of the system unit and peripherals. The system unit is the main component of the computer and it houses the central processing unit (CPU), motherboard, control unit and other essential components. The CPU is the brain of the computer and it processes instructions that are sent to it. The motherboard is the main circuit board that connects all the other components in the computer such as the CPU, memory, and storage devices. The control unit is responsible for managing the flow of data within the CPU. Peripherals are devices that are connected to the computer system to extend its capabilities. Examples of peripherals include input devices like the keyboard and mouse, output devices such as the monitor and printer, and storage devices such as external hard drives. In summary, the system unit is the main component of the computer system that contains the essential components like CPU, motherboard, and control unit, while peripherals are external devices that are connected to the computer to expand its functionality.

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The hardware of a computer refers to the physical components that make up a computer system. These components include the casing or chassis, motherboard, CPU, RAM, hard drive, power supply, and peripherals such as a monitor, keyboard, and mouse. Windows, on the other hand, is a software operating system and not a hardware component, therefore it is the correct answer to the question.

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Charles Babbage was the first to invent the analytical engine, which is considered to be the world's first general-purpose computer. The analytical engine was designed to perform complex mathematical calculations and was programmable using punched cards. Although Babbage was not able to complete the construction of the analytical engine during his lifetime, his work laid the foundation for the development of modern computers. Therefore, the correct answer is "invent analytical engine".

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The network that covers the widest range is the WAN (Wide Area Network). WAN covers a large geographical area, often spanning multiple cities or even countries. It connects multiple LANs (Local Area Networks) and MANs (Metropolitan Area Networks) together over a long distance through various communication channels like satellites, leased lines, or wireless links. In other words, WAN is like a superhighway that connects different LANs and MANs, allowing people and organizations from different parts of the world to communicate with each other. WANs are commonly used by large companies, governments, and universities for various purposes, such as sharing data, accessing remote resources, and connecting remote offices. On the other hand, LANs are used in small offices, homes, or buildings to connect devices within a small area, while MANs connect multiple LANs within a city or metropolitan area. PANs (Personal Area Networks) are even smaller networks used for personal devices like smartphones, laptops, and wearable devices, typically within a range of a few meters.

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The color palette in CorelDraw allows the user to choose and apply different colors to their designs. It provides a wide range of color options and allows users to create custom colors as well. With the color palette, users can easily select and apply colors to various elements of their design, such as text, shapes, and images. It helps users to achieve their desired color scheme and make their designs more visually appealing. Additionally, it also allows users to save and reuse their favorite or frequently used colors.

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The device that is not a mobile input device is the Scanner. A mobile input device is a device that allows you to input data into a mobile device or a computer while you are on the go. Joystick, Light pen, and Mouse are all examples of mobile input devices. A joystick is an input device that is used to control the movement of objects on a screen, such as gaming characters or drones. A light pen is a device that allows you to draw or write on a screen by detecting the light emitted by the screen. It is often used in graphic design or art. A mouse is an input device that allows you to move a cursor on the screen, select items, and perform other tasks by clicking buttons. On the other hand, a scanner is an output device that allows you to scan and convert physical documents or images into digital formats. While you can use a scanner with a mobile device or a computer, it is not considered a mobile input device because it requires a flat surface and it is not designed for on-the-go use.

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The valid e-mail address among the options given is "waeconline@yahoo.co.uk". An e-mail address is a unique identifier that enables users to send and receive electronic messages through the internet. It consists of two main parts: the local part and the domain part. The local part typically contains a user's username or alias, and the domain part specifies the domain name of the email service provider. In the options given, only "waeconline@yahoo.co.uk" follows the standard format for e-mail addresses. It contains a valid username "waeconline" and a valid domain name "yahoo.co.uk". The other options "www.itbeginswithu.org", "www.waeconline.org", and "www.fine.gov.ng" are not valid e-mail addresses because they do not follow the standard format for e-mail addresses. They contain web addresses or URLs, which are used to identify websites on the internet, but they cannot be used to send or receive e-mails.

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EDVAC is not a microcomputer. EDVAC (Electronic Discrete Variable Automatic Computer) was one of the earliest electronic digital computers, developed in the 1940s. It was a large mainframe computer that filled a room and was used for scientific and military purposes. On the other hand, desktops, laptops, and notebooks are all examples of microcomputers. They are small and relatively inexpensive compared to mainframe and supercomputers, and are designed for personal and business use. In summary, while desktops, laptops, and notebooks are all examples of microcomputers, EDVAC is not a microcomputer and is instead a mainframe computer.

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The content of cell D3 is 5678. The table shows the number of books supplied to Senior High School (SHS) students for three different forms (Maths, ICT, and English Language) and three different levels (SHS I, SHS II, and SHS III). The content of cell D3 represents the number of books supplied for English Language in SHS I. Therefore, the correct answer is 5678.

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To convert a binary number to base ten, you need to multiply each digit of the binary number by its corresponding power of two, starting from the rightmost digit with the power of zero, and adding up the results. In this case, we have the binary number 11001\(_2\). Starting from the rightmost digit with the power of zero, we have: 1 × 2\(^0\) = 1 0 × 2\(^1\) = 0 0 × 2\(^2\) = 0 1 × 2\(^3\) = 8 1 × 2\(^4\) = 16 Adding up these results, we get: 1 + 0 + 0 + 8 + 16 = 25 Therefore, the conversion of 11001\(_2\) to base ten is 25.

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(a) What is a computer file?

A computer file is a collection of related records or data stored together under one name on a storage medium, and treated as a single unit by the computer.

(b) Two features each

(i) Transaction file:

1. It holds temporary data about current transactions or events (for example daily sales) that are used to update the master file.
2. Its contents change frequently and it is usually not kept for long after the master file has been updated.

(ii) Reference file:

1. It holds fairly permanent data that is looked up (referred to) when processing, for example price lists or tax rates.
2. Its contents change only occasionally and it is used mainly for reference, not for continuous updating.

(c) Two of each

(i) Effects of file insecurity:

1. Loss, damage or corruption of data.
2. Unauthorised access, alteration or theft of confidential information.

(ii) Methods of securing files:

1. Use of passwords and access rights.
2. Encryption of files (and keeping regular backups / using anti-virus and write-protection).

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(a) Two main constituents of a computer

1. Hardware (the physical parts of the computer).
2. Software (the programs that run on the computer).

(b) Four characteristics of a computer

1. Speed - it processes data very fast.
2. Accuracy - it gives correct results with very few errors.
3. Storage - it can store very large amounts of data.
4. Diligence / automation - it can work continuously without getting tired. (Versatility is also acceptable.)

(c) Categorising the statements as data or information

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(a) Definition of algorithm

An algorithm is a finite set of clear, step-by-step instructions for solving a particular problem, arranged in a logical order so that following the steps produces the required result.

(b) Three characteristics of an algorithm

1. Finiteness - it must have a definite ending after a finite number of steps.
2. Effectiveness with input and output - it must take input (where needed) and produce at least one output, and every step must be doable. (Being general/applicable to a class of problems is also acceptable.)

(c) Algorithm for finding the average of numbers when the sum is given

The average is the sum divided by the count of numbers, \(Average = \dfrac{Sum}{N}\).

1. Start.
2. Read the sum of the numbers, SUM.
3. Read the count of the numbers, N.
4. If N = 0, display "cannot divide by zero" and go to step 7.
5. Compute AVERAGE = SUM / N.
6. Display AVERAGE.
7. Stop.

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(a) Definition of operating system

An operating system is the system software that controls and manages the hardware and software resources of a computer, and acts as an interface between the user and the computer, enabling other programs to run. Examples are Windows, Linux, macOS and Android.

(b) Two functions of an operating system

1. It manages the hardware resources (processor, memory, input/output devices and storage).
2. It provides a user interface and controls the loading and running of application programs (and manages files and security).

(c) Two types of each

(i) Application software:

1. Word processing software (for example Microsoft Word).
2. Spreadsheet software (for example Microsoft Excel). (Database and presentation software are also acceptable.)

(ii) Translators:

1. Compiler.
2. Interpreter. (Assembler is also acceptable.)

(d) Two software to compile the personal data of final year students

1. Database software (for example Microsoft Access) to store and manage the student records.
2. Spreadsheet software (for example Microsoft Excel), or word processing software, to enter and tabulate the data.

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(a) Definition of system development cycle

The system development cycle (system development life cycle) is the series of stages or steps followed in an orderly way to plan, analyse, design, build, test and put into use a new information system, and then to maintain it.

(b) Four stages involved in the system development cycle

1. Problem definition / feasibility study (identify the problem and decide whether a new system is worthwhile).
2. System analysis (study the existing system and gather requirements).
3. System design (design the inputs, processes, outputs and files of the new system).
4. Implementation, testing and maintenance (build, test, install the system and keep it running).

(c) Four qualities of a good program

1. Correctness / accuracy - it produces the right results.
2. Reliability - it works consistently without failing.
3. User-friendliness - it is easy to understand and use.
4. Maintainability - it is well structured and easy to modify. (Efficiency and portability are also acceptable.)