WAEC SSCE - Computer Studies - 2014

Maelezo ya Majibu

Saving documents without a password is not a suitable method for securing files. When files are saved without a password, anyone with access to the computer or storage device can open and modify them. This means that sensitive or confidential information can be accessed and tampered with by unauthorized persons. Therefore, it is important to use passwords or other security measures to protect files from unauthorized access or modification. The other options mentioned - use of backup, use of antivirus, and proper labelling of storage devices - are all suitable methods for securing files, as they help to prevent data loss, protect against malware or viruses, and ensure that storage devices are properly identified and managed.

Maelezo ya Majibu

An advantage of Graphical User Interface (GUI) over Disk Operating System (DOS) is that it allows the use of a mouse. In a DOS environment, users typically have to rely on keyboard commands to navigate and operate the system. On the other hand, a GUI interface uses graphical elements such as icons, menus, and windows that can be easily manipulated with a mouse. This makes the interface more intuitive and user-friendly, especially for those who are not familiar with command-line interfaces. The mouse allows users to point and click on icons or other visual elements, which can trigger actions or open files and applications. This makes it easier to interact with the computer and perform various tasks.

Maelezo ya Majibu

The statement that is not true about a computer file is: "Initial setup is inexpensive". Explanation: - "It is very fast to access any record within a file": This statement is true as accessing data within a computer file is much faster than accessing data from physical documents. - "It is created electronically": This statement is also true as computer files are created and stored in digital format. - "File creation and access are less laborious": This statement is true because creating and accessing files is much easier and less time-consuming than managing physical documents. However, the statement "Initial setup is inexpensive" is not always true. While creating a file may not require significant expenses, the initial setup of a system to manage and store files (such as a computer, software, or cloud storage service) can be costly.

Maelezo ya Majibu

The application software which allows information available on the internet to be obtained is called a "browser". A browser is a software application used to access and view websites, web pages, and other content available on the internet. It allows users to navigate the web by entering URLs or search terms to find information, and presents the content in a user-friendly way, including text, images, videos, and other media. Popular browsers include Google Chrome, Mozilla Firefox, Microsoft Edge, and Apple Safari.

Maelezo ya Majibu

The path labelled I in Fig.2 is the Feasibility Study. This is the initial stage in the System Development Cycle where the feasibility of the proposed system is evaluated. The feasibility study examines the economic, technical, operational, schedule, and legal feasibility of the system. In this stage, the project's goals, objectives, and constraints are identified, and alternative solutions are evaluated. A feasibility study helps the development team to determine whether the proposed system is worth developing, and if so, what resources will be required to develop the system.

Maelezo ya Majibu

Charles Babbage is best known for designing two mechanical computing devices, the Difference Engine and the Analytical Engine. The Difference Engine was designed to compute tables of numbers, while the Analytical Engine was designed to be a general-purpose computer capable of performing any computation that could be carried out by a human computer. Therefore, the correct answer is "Difference Engine and Analytical Engine."

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

In Fig.3, the part labelled II represents the process symbol. In a flowchart, process symbols represent actions or operations performed on data, such as calculations or transformations. Therefore, in this flowchart, the process symbol II represents the action or operation being performed on the input data.

Maelezo ya Majibu

A webcam is not an output device. It is a device that captures video and audio and sends it to another device or computer. The other options, plotters, speakers, and projectors are all output devices. Plotters are used to produce high-quality graphics, while speakers are used to produce sound, and projectors are used to display visual images on a screen or surface.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

The acronym HTTP stands for "Hyper Text Transfer Protocol". It is a protocol or set of rules used for transferring and receiving web pages, documents, and other resources on the World Wide Web. This protocol is responsible for facilitating communication between web servers and clients, such as web browsers. The client sends an HTTP request message to the server, and the server responds with an HTTP response message containing the requested resource. The HTTP protocol is an essential part of the Internet, and it is the foundation upon which the World Wide Web is built.

Maelezo ya Majibu

In ring topology, the computer that is allowed to transmit data possesses the "Token". A token is a small data packet that circulates around the network in a specific order. When a computer wants to transmit data, it must wait until it receives the token. Once the computer receives the token, it can transmit data onto the network, and the token will move on to the next computer in the ring. In this way, the token acts as a way to control access to the network and prevent multiple computers from transmitting data at the same time, which could cause collisions and data loss.

Maelezo ya Majibu

The number of cells that contain data in row 1 is 5. This is because each cell in row 1 (from column A to column E) contains data. The data in row 1 represents the book supplied to senior high schools and the subjects for which the book was supplied. Therefore, there are 5 cells in row 1 that contain data.

Maelezo ya Majibu

Computer hardware refers to the physical components of a computer system. It can be broadly classified into two categories: system unit and peripherals. The system unit includes the Central Processing Unit (CPU), which is responsible for processing data, and other components such as motherboard, memory, and storage devices. The peripherals include input devices such as keyboard and mouse, output devices such as monitor and printer, and other devices such as scanners and speakers. Therefore, the correct answer is "System Unit and Peripheral".

Maelezo ya Majibu

Machine language does not need a translator for it to run. This is because machine language is written in binary code, which is the language that computers use to process instructions. Unlike other programming languages, machine language can be executed directly by the computer's CPU without the need for any translation. Therefore, the correct answer is machine language.

Maelezo ya Majibu

The ENIAC was the first electronic general-purpose computer that was built in the mid-1940s, long after the pre-computing age and the 19th century. Therefore, the answer is ENIAC. - Napier's bone: A manual calculating device invented by John Napier in the early 17th century. - Abacus: A manual calculating device that has been used for thousands of years, dating back to ancient times. - Slide rule: A mechanical analog computer used for multiplication, division and other mathematical calculations. It was widely used from the 17th to the late 20th century. So, the computing device that did not exist in the pre-computing age to the 19th century is ENIAC.

Maelezo ya Majibu

Coreldraw is the software used for graphic production. It is a vector graphics editor developed and marketed by Corel Corporation. It is used to create illustrations, logos, brochures, and other design-related tasks. Coreldraw provides tools for drawing lines and shapes, editing images, and creating text. It is widely used in the graphic design industry due to its versatility, user-friendly interface, and powerful tools for creating high-quality graphics. On the other hand, DOS Editor, PC Writer, and Acrobat Reader are not specifically designed for graphic production, but they have other functions.

Maelezo ya Majibu

The BASIC statement LET Z = 4*W^2 + 2*Y can be evaluated by replacing the variables W and Y with their respective values, which are given as W = 5 and Y = 10. Substituting these values, we get: Z = 4*(5)^2 + 2*(10) Z = 4*25 + 20 Z = 100 + 20 Z = 120 Therefore, the value of Z is 120. The correct option is (d).

Maelezo ya Majibu

The property of a disk that determines the amount of data it may contain is the "storage capacity". Storage capacity refers to the amount of data that can be stored on a disk or any other digital storage medium. It is usually measured in bytes (such as gigabytes or terabytes) and is determined by the physical size of the storage device and the technology used to store the data. The larger the storage capacity of a disk, the more data it can hold.

Maelezo ya Majibu

In a computer's central processing unit (CPU), the instruction fetched from the memory is decoded by the control unit. The control unit is responsible for controlling the flow of data within the CPU, including retrieving instructions from memory, decoding them, and executing them. It manages the sequence of operations that the CPU performs to carry out instructions, and it communicates with other components of the CPU, such as the arithmetic logic unit (ALU) and the program counter, to ensure that the correct operation is performed. Therefore, the correct answer is the control unit.

Maelezo ya Majibu

The best software for keeping records during national population census is a database. This is because a database is specifically designed for managing large amounts of structured data and provides powerful tools for data input, storage, retrieval, and analysis. With a database, census data can be organized in a systematic and meaningful way, making it easier to manage, update and extract relevant information when needed. Word processing software is primarily used for creating and editing text-based documents, while spreadsheets are used for numerical calculations and data analysis. Graphics software is used for creating visual content such as images and charts. While all of these software types may be used in the census process, a database is the most suitable option for managing large and complex datasets.

Maelezo ya Majibu

The statement that is true about registers is: "It is a special high speed storage area within the CPU." Registers are a small, fast storage area within the central processing unit (CPU) that temporarily holds data and instructions that the CPU is currently processing. Registers are very fast compared to other forms of computer memory, such as RAM, because they are located directly within the CPU and are designed to be quickly accessible. Registers are used to hold data that the CPU is currently working on, such as numbers, characters, and memory addresses, as well as instructions that tell the CPU what to do with that data.

Maelezo ya Majibu

The process of restarting a computer is known as "Warm booting". Warm booting means restarting a computer while it is already turned on, without turning off the power. During a warm boot, the system goes through a process called "reset" which shuts down and restarts the operating system and all the software programs that are running. This is usually done when the computer is not responding properly, or when a software installation requires a restart. It is called "warm" because the computer components are not completely powered off and the system does not have to perform a complete power-on self-test (POST) as in a cold boot.

Maelezo ya Majibu

Maelezo ya Majibu

Copyright protects the expression of ideas, not the ideas themselves. In other words, if someone comes up with an idea, such as a new invention or a story, they cannot copyright the idea itself. However, if they express that idea in a tangible form, such as by writing it down or recording it, then that expression is protected by copyright. Therefore, the option that is protected by copyright is "Expression of ideas".

Maelezo ya Majibu

The outcome of a processed data in a computer is known as information. When data is processed by a computer, it is transformed into a meaningful and useful form that can be easily understood by the user. This processed data is known as information because it provides knowledge or insight that can be used to make decisions, solve problems or perform tasks. Information can be in the form of text, numbers, graphics, audio, or video. It is the result of applying various operations to raw data, such as sorting, filtering, aggregating, analyzing, and presenting it in a format that can be easily understood by humans. Therefore, information is the final output of a computer system that is intended to be used by people for various purposes.

Maelezo ya Majibu

In the hexadecimal number system, each digit represents a value from 0 to 15. The first ten digits represent their respective values, and the next six are represented by the letters A to F, which represent values from 10 to 15. Therefore, B represents the value 11, D represents the value 13, and E represents the value 14. So, the correct option is: B, D, E represent 12, 14, 15 respectively.

Maelezo ya Majibu

The sets of instruction that direct a computer in performing a particular task is called a "program". A program is a collection of instructions that are written in a specific programming language to tell a computer what to do. Programs can perform a wide range of tasks such as word processing, image editing, web browsing, playing games, and much more. Programs are executed by the computer's CPU (Central Processing Unit) in a sequential order to perform a specific task.

Maelezo ya Majibu

The subscript "10" indicates that 26 is a number written in base 10 (decimal), which means that it uses 10 digits (0-9) to represent all possible values. The subscript "2" indicates that X is a number written in base 2 (binary), which means that it uses only 2 digits (0 and 1) to represent all possible values. To convert 26 from base 10 to base 2, we can use the repeated division-by-2 algorithm: - Divide 26 by 2: 26 ÷ 2 = 13 with a remainder of 0 (LSB) - Divide 13 by 2: 13 ÷ 2 = 6 with a remainder of 1 - Divide 6 by 2: 6 ÷ 2 = 3 with a remainder of 0 - Divide 3 by 2: 3 ÷ 2 = 1 with a remainder of 1 - Divide 1 by 2: 1 ÷ 2 = 0 with a remainder of 1 (MSB) The remainders, read from bottom to top, give the binary representation of 26: 11010. Therefore, the answer is option (B) 11010.

Maelezo ya Majibu

Maelezo ya Majibu

The most cost-effective and secure way of transmitting confidential messages among the employees of an organization is the use of email. Email is a method of exchanging digital messages between people using electronic devices, which can be used to transmit confidential messages among employees of an organization in a secure and cost-effective manner. Confidential email messages can be encrypted to ensure that they can only be read by the intended recipient, making it a secure means of communication. Electronic notice boards, teleconferencing, and social networks are not as secure or reliable as email for transmitting confidential messages among employees.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

The correct association between a hardware component and its function is: - Mouse to input: A mouse is an input device that allows users to interact with the computer by moving the cursor on the screen and clicking on icons, buttons, or other graphical elements. - Monitor to display: A monitor is an output device that displays text, images, and video on the screen. - CPU to processing: The Central Processing Unit (CPU) is the brain of the computer and performs most of the processing tasks. It executes instructions, performs calculations, and manages data flow between other components. - Hard disk to storage: A hard disk is a non-volatile storage device that stores data on spinning disks coated with magnetic material. It provides long-term storage for files, programs, and operating systems. Therefore, the correct association between a hardware component and its function is: Mouse to input, Monitor to display, CPU to processing, and Hard disk to storage.

Maelezo ya Majibu

Maelezo ya Majibu

The term hardcopy refers to a printout of information or data that has been produced by a printer or other output device. It is a physical, tangible copy of information that can be held and stored, unlike digital copies of data that are stored on electronic devices. Therefore, the best item that describes the term hardcopy is "Print out."

Maelezo ya Majibu

The EDVAC is not a microcomputer. EDVAC stands for Electronic Discrete Variable Automatic Computer, which was one of the earliest electronic computers. It was designed and built during the 1940s and was a large-scale computer that was not small or inexpensive enough to be considered a microcomputer. On the other hand, notebook, laptop, and desktop computers are all examples of microcomputers or personal computers that are small enough to be used by an individual.

Maelezo ya Majibu

Maelezo ya Majibu

The command to use in changing the storage location of a file is the 'save as' command. This command allows the user to save a copy of the file with a new name or in a new location while preserving the original file in its current location. The 'save' command simply saves changes made to the current file in its current location without offering the option to change the file name or location. The key combination 'ctrl + S' is a shortcut for the 'save' command, and 'alt + F, then save' is a sequence of keys that accesses the 'save' command through the file menu. Therefore, the correct option is 'save as' command.

Maelezo ya Majibu

Maelezo ya Majibu

The part labelled III in Fig.3 flowchart represents a decision symbol. A decision symbol is used in a flowchart to represent a point where a decision has to be made, which can lead to different paths or outcomes depending on the result of the decision. In this case, the decision symbol labelled III represents a decision that asks whether a particular condition is true or false, and the outcome of this decision will determine which path the flowchart follows next.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

To convert a binary number to base 10, we start by writing down the binary digits of the number and assigning a place value to each digit, based on its position. The rightmost digit has a place value of 1, the next digit to the left has a place value of 2, then 4, 8, and so on, doubling each time. We then multiply each binary digit by its corresponding place value and add up the products. For the given binary number 11001, we can assign the following place values: 1 1 0 0 1 16 8 4 2 1 Multiplying each digit by its corresponding place value and adding up the products, we get: 1×16 + 1×8 + 0×4 + 0×2 + 1×1 = 16 + 8 + 1 = 25 Therefore, the conversion of 11001 \(_2\) to base 10 equals 25.

Maelezo ya Majibu

Maelezo ya Majibu

The transaction file is a type of file used in computer systems to store records of individual transactions. These transactions can be of various types, such as financial transactions, inventory transactions, or customer transactions. Each record in the transaction file typically includes information such as the date and time of the transaction, the transaction amount, and any other relevant details. Unlike a master file, which contains the current state of a set of records, a transaction file contains information about changes that have been made to those records over time. For example, a transaction file for a bank might contain records of all deposits, withdrawals, and transfers made by customers over a given period of time. Therefore, the answer to the question is "Movement file".

Maelezo ya Majibu

In Fig. 1, the circle represents the NOT gate, which means it has only one input and one output. Since there are two NOT gates, it means there are two input signals (X and Y) and one output signal (Z). Therefore, the answer is: Input, Input and Output signals.

Maelezo ya Majibu

(a)(i) Definition of Information and Communication Technology (ICT)

Information and Communication Technology is the use of computers, telecommunication equipment and related electronic devices, together with the necessary software, to gather, process, store, retrieve and transmit information from one place to another.

(a)(ii) Three uses of ICT in the banking sector

1. Automated Teller Machines (ATM): customers withdraw cash, check balances and transfer funds electronically without a cashier.
2. Online / Internet and mobile banking: customers operate their accounts, pay bills and transfer money over the Internet or a mobile app.
3. Electronic funds transfer and cheque/record processing: banks move money between accounts and keep customer records in databases, and use ICT for card payments and account statements.

(Other acceptable uses: electronic clearing of cheques, SMS/e-mail alerts, and a networked ledger shared among branches.)

(b) Full meaning of the acronyms

• LAN - Local Area Network
• GPS - Global Positioning System
• IP - Internet Protocol

Maelezo ya Majibu

(a) Matching each ICT type with its relevant communication sector. The four sectors listed (Radio, Internet, GSM, video conferencing) belong to the ICT types as follows:

Reasoning: Broadcasting is the ICT used to transmit radio (and television) programmes; a data network carries traffic for the Internet; telecommunication covers voice/mobile telephony such as GSM; and satellite communication provides the long-distance links that make video conferencing possible.

(b) Three computing devices for each period:

(i) 19th century (1800s):

• Difference Engine (Charles Babbage)
• Analytical Engine (Charles Babbage)
• Hollerith's Tabulating Machine / punched-card machine (Herman Hollerith)

(ii) 20th century (1900s):

• Harvard Mark I
• ENIAC
• UNIVAC (and the personal/desktop computer)

Maelezo ya Majibu

(a) Definition of programming language

A programming language is a set of symbols, words and grammatical rules (syntax) used to write instructions that a computer can understand and carry out to solve a problem. Examples are BASIC, C, Java and Python.

(b) The expressions in BASIC notation

• (i) \(x(w + y)^2\) is written as X * (W + Y) ^ 2
• (ii) \(\dfrac{ab}{cd}\) is written as (A * B) / (C * D)
• (iii) \(p = 2(1 + b)\) is written as P = 2 * (1 + B)

(c) BASIC program to calculate the area (A) of a rectangle

The area of a rectangle is length multiplied by breadth, \(A = l \times b\).

10 REM PROGRAM TO FIND AREA OF A RECTANGLE
20 INPUT "ENTER LENGTH"; L
30 INPUT "ENTER BREADTH"; B
40 A = L * B
50 PRINT "AREA OF RECTANGLE = "; A
60 END

(d) Two levels of programming language

1. Low-level language (machine language and assembly language).
2. High-level language (such as BASIC, C, Java and Python).

Maelezo ya Majibu

(a) Three criteria used in classifying files

1. Nature / purpose of the file (for example master file, transaction file, reference file, backup file).
2. Organisation or method of access (serial, sequential, indexed-sequential or random/direct access).
3. Type of content or storage medium (for example text, program, data or graphic files; or the medium such as disk or tape file).

(b)(i) Advantages and disadvantages of computer files

Two advantages:

1. Large volumes of data can be stored in a small space and retrieved quickly.
2. Files can be easily updated, sorted, copied and shared, and they reduce paperwork.

Two disadvantages:

1. Files can be lost or corrupted through virus attack, disk failure or power problems.
2. Data in files can be accessed or altered by unauthorised persons if not properly secured, and recovery may be costly.

(b)(ii) Three methods of file security

1. Use of passwords and access rights so that only authorised users can open or edit the file.
2. Encryption of the file so that its contents cannot be read without the key.
3. Regular backup of files (and use of anti-virus software / write-protection) so that data can be restored if the original is lost.

Maelezo ya Majibu

None