Computer Basics PDF

Q: What is a computer?  A: A computer is an electronic device that operates under the control of instructions stored in its memory. It can accept data, process it according to specified rules, produce results, and store them for future use. Q: What is the Information Processing...

Q: What is a computer?  A: A computer is an electronic device that operates under the control of instructions stored in its memory. It can accept data, process it according to specified rules, produce results, and store them for future use. Q: What is the Information Processing Cycle?  A: The Information Processing Cycle involves the following activities: 1. Data input. 2. Data processing using instructions. 3. Output of information. 4. Storage of results for future use. o Communication has become an essential part of the cycle, as computers now interact with each other. Q: What are the components of a computer?  A: The main components include: o Input Devices: Such as the keyboard, mouse, microphone, scanner, and webcam. o Output Devices: Such as printers, monitors, and speakers. o System Unit: Houses the motherboard, which includes the processor (CPU) and memory. o Storage Devices: Such as hard disks, USB drives, optical discs, and memory cards. o Communication Devices: Such as modems for data exchange between devices. Q: What are the characteristics of a computer?  A: Computers are characterized by: o Speed, reliability, accuracy, storage capability, and communication features. Q: What are computer networks?  A: A network is a collection of connected devices, often wirelessly, that share resources like hardware, software, and data. The Internet is the world’s largest network. Q: What are the uses of the Internet?  A: People use the Internet for: o Communication, research, shopping, entertainment, training, sharing information, and downloading files. Q: What are the risks associated with computer usage?  A: The risks include: o Health Risks: Prolonged or improper use can cause injuries to the neck, wrists, or back. o Privacy Violations: Personal data could be stolen or misused. o Public Safety: Sharing personal information online could expose users to risks. Q: What is computer software?  A: Computer software refers to programs that execute on hardware to perform specific tasks. It is divided into two types: o System Software: Provides basic functionality, controls hardware, and acts as an interface (e.g., operating systems, device drivers). o Application Software: Used by users for specific tasks (e.g., web browsers, word processors). Q: What is an operating system (OS)?  A: An OS is a special program that: o Manages hardware resources. o Provides a user interface. o Allows users and application software to interact with hardware without needing to understand the hardware details. o Examples: Windows, Android, Linux, UNIX. Q: What are the main functions of an operating system?  A: o Process Management. o Memory Management. o File Management. o Device Management. o Security and Protection. o User Interface (Command Line or Graphical User Interface). Q: What types of operating systems exist?  A: o Single-user, single-task (e.g., MS-DOS). o Single-user, multi-tasking (e.g., Windows). o Multi-user, multi-tasking (e.g., UNIX). o Real-Time Operating Systems (RTOS). o Embedded Systems (e.g., traffic systems, microwaves).  Q: What are programming languages? o A: A programming language includes a set of vocabulary and rules for expressing computations. Types include:  Machine Language: The most basic level.  Assembly Language: Uses mnemonics.  High-Level Language (HLL): Easier to use, e.g., Python, C++. Q: What is translator software? o A: Translator software converts programs into machine language. Types:  Compiler: Translates the entire program at once; faster execution (e.g., C++, Java).  Interpreter: Translates and executes line by line; easier to debug (e.g., Python). Q: What is application software? o A: Programs designed for specific purposes:  General-Purpose Applications: Word processing, spreadsheets, web browsers, CAD/CAM.  Specialized Applications: Focus on specific disciplines or problems. Q: How is software acquired? o A:  Retail Software: Off-the-shelf.  OEM Software: Bundled with hardware.  Demo Software: Restricted features for demonstration.  Shareware: Free trial for a limited time.  Freeware: Free for personal use. Q: What types of operating systems exist?  A: o Single-user, single-task (e.g., MS-DOS). o Single-user, multi-tasking (e.g., Windows). o Multi-user, multi-tasking (e.g., UNIX). o Real-Time Operating Systems (RTOS). o Embedded Systems (e.g., traffic systems, microwaves). Q: What are programming languages?  A: A programming language includes a set of vocabulary and rules for expressing computations. Types include: o Machine Language: The most basic level. o Assembly Language: Uses mnemonics. o High-Level Language (HLL): Easier to use, e.g., Python, C++. Q: What is translator software?  A: Translator software converts programs into machine language. Types: o Compiler: Translates the entire program at once; faster execution (e.g., C++, Java). o Interpreter: Translates and executes line by line; easier to debug (e.g., Python). Q: What is application software?  A: Programs designed for specific purposes: o General-Purpose Applications: Word processing, spreadsheets, web browsers, CAD/CAM. o Specialized Applications: Focus on specific disciplines or problems. Q: How is software acquired?  A: o Retail Software: Off-the-shelf. o OEM Software: Bundled with hardware. o Demo Software: Restricted features for demonstration. o Shareware: Free trial for a limited time. o Freeware: Free for personal use. o Public Domain Software: Free with no copyright. o Open-Source Software: Free, with customizable source code. 1. Q: What is data representation in computers? o A: Data in computers can take the form of numbers, text, audio, images, or videos. All types of data are encoded using the binary system (0s and 1s) to be processed or stored. Q: What are the types of number systems used in computers? o A: The main number systems are:  Decimal (Base 10): Uses digits 0-9.  Binary (Base 2): Uses digits 0 and 1.  Octal (Base 8): Uses digits 0-7.  Hexadecimal (Base 16): Uses digits 0-9 and letters A-F. Q: How are numbers converted between number systems? o A:  From Decimal to Other Bases: Use repeated division (for integers) or multiplication (for fractions) by the target base.  From Binary to Octal/Hexadecimal: Group binary digits into sets of 3 (Octal) or 4 (Hexadecimal) and convert each group.  From Hexadecimal/Octal to Binary: Convert each digit directly into binary equivalents. Q: What is binary arithmetic? o A: Binary arithmetic involves performing addition, subtraction, multiplication, and division using the binary number system. It follows rules specific to binary logic, such as carrying over in addition or borrowing in subtraction. Q: What is floating-point binary data representation? o A: Floating-point representation is used for real numbers. It divides a number into a mantissa and an exponent, allowing for representation of very large or small values. Q: How is text data represented in computers?  o A: Text is encoded into binary using character encoding schemes such as:  ASCII: Represents characters using 7 or 8 bits.  Unicode: Supports a wide range of characters and uses up to 32 bits per character. Q: Provide an example of converting a number between bases. o A: Convert (25)₁₀ to Binary, Octal, and Hexadecimal:  Binary: (25)₁₀ = (11001)₂.  Octal: (25)₁₀ = (31)₈.  Hexadecimal: (25)₁₀ = (19)₁₆. Q: How do you convert a binary number to hexadecimal? o A: Group the binary digits into sets of 4 starting from the right (add leading zeros if necessary) and convert each group to its hexadecimal equivalent. Example:  Binary: (1110101100110)₂ = (1D66)₁₆. Q: What is the Software Development Life Cycle (SDLC)?  A: The SDLC includes the following steps: 1. Planning (Problem Definition): Identify the problem scope and solution requirements. 2. Problem Analysis: Specify the program’s inputs, processes, outputs, and interface. 3. Design: Develop a logic plan using algorithms, flowcharts, or pseudo-code. 4. Implementation: Write the code using a programming language. 5. Testing and Integration: Debug and ensure the program functions correctly. 6. Maintenance: Provide user support, fix errors, and implement enhancements. o Retirement: End-of-life for software when it is replaced by a new version or application. Q: What is an algorithm?  A: An algorithm is a finite, ordered sequence of clear instructions to complete a task. o Example: To find the area of a circle: 1. Input the radius rrr. 2. Compute the area using Area=π⋅r2\text{Area} = \pi \cdot r^2Area=π⋅r2. 3. Print the result. Q: What are the basic control structures of algorithms?  A: 1. Sequential: Execute instructions in order. 2. Selection (Conditional): Choose between instructions based on a True/False condition. 3. Iteration (Loop): Repeat a set of instructions until a condition is met. Q: What is a flowchart?  A: A flowchart is a graphical representation of the logic for solving a task, using symbols to depict the steps in an algorithm. Q: What is pseudo-code?  A: Pseudo-code is a simplified, human-readable description of the steps in an algorithm, written in structured English. o Examples of terms used:  For input: INPUT, READ.  For output: PRINT, DISPLAY.  For calculations: CALCULATE, COMPUTE. Q: Provide an example of an algorithm to find the largest of three numbers.  A: 1. Input three numbers AAA, BBB, CCC. 2. Compare AAA and BBB:  If A>BA > BA>B, compare AAA with CCC:  If A>CA > CA>C, AAA is the largest. Otherwise, CCC is the largest.   If B>AB > AB>A, compare BBB with CCC:  If B>CB > CB>C, BBB is the largest. Otherwise, CCC is the largest. Q: Why is documentation important in software development?  A: o Internal Documentation: Helps other programmers understand the code and its purpose. o External Documentation: Includes user manuals, instructions, and support materials such as FAQs. Q: What is system development?  A: System development is the process of creating software or an information system. It includes: o System analysis: Understanding the current environment and defining requirements. o System design: Converting requirements into a plan. o System development: Implementing the design in code. o Maintenance: Supporting users and updating the system. Q: What are the main approaches to system development?  A: 1. Waterfall Model: Sequential development stages with full documentation. Best for large-scale projects but takes more time. 2. Agile Method: Incremental development with smaller, prioritized features. Focuses on rapid development and adaptability. Q: What are the types of applications?  A: o Desktop Applications: Installed on a local computer, e.g., calculators, word processors. o Web Applications: Run on a client-server model via a web browser, e.g., webmail. o Mobile Applications: Installed on mobile devices like smartphones or tablets, e.g., games and utility apps. Q: What are the phases of system development?  A: 1. System Analysis: Explore the current situation and define requirements. 2. System Design: Plan the architecture and components. 3. Implementation: Write code and build the system. 4. Testing and Maintenance: Debug the system and ensure smooth operation. Q: What is Object-Oriented Programming (OOP)?  A: OOP is a programming paradigm that organizes code into objects containing data (attributes) and functions (methods). o Example: A Student object can have attributes like name and GPA, and methods like calculate_GPA(). o Advantages: Organized code, easier updates, reusability through classes, and modularity. Q: What is testing in system development?  A: Testing ensures that the system works as expected and involves: o Unit Testing: Testing individual components for programming and logical errors. o Integration Testing: Ensuring that different system components work together cohesively. o Test Plans: Predefined steps and expected results to validate the system. Q: What tools and programming paradigms are used in software development?  A: o Programming Languages: C++, Java, Python, etc. o Compilers: Translate high-level code to machine code. o Integrated Development Environments (IDEs): Provide tools like editors, debuggers, and linkers for efficient development. o OOP Languages: Many modern languages support OOP for better code organization. Q: What is an Operating System (OS)?   A: An operating system is software that acts as an intermediary between computer hardware and applications, providing essential services to enable user and application interaction with the hardware. Q: What are the basic functions of an operating system?  A: 1. Process Management: Manages processes, allocates resources, and ensures smooth operation. 2. Memory Management: Handles memory allocation and ensures processes do not interfere with each other. 3. File System Management: Organizes data on storage devices and enables file operations. 4. Device Management: Provides communication between hardware and applications. 5. User Interface (UI): Allows users to interact with the computer (CLI, GUI, or VUI). Q: What are the main components of an OS?  A: o Kernel: Core of the OS that manages resources and provides services. o Device Drivers: Facilitate communication between the OS and hardware. o File System: Manages data storage organization. o User Interface: Includes Command-Line Interface (CLI), Graphical User Interface (GUI), and Voice User Interface (VUI). Q: What are the types of operating systems?  A: 1. Single-User, Single-Tasking: Supports one user and one task at a time (e.g., early MS-DOS). 2. Single-User, Multi-Tasking: Allows one user to run multiple programs simultaneously (e.g., Windows, macOS). 3. Multi-User: Supports multiple users simultaneously (e.g., Unix). 4. Real-Time OS (RTOS): Provides immediate and predictable responses, used in embedded systems. Q: How has the evolution of OS progressed?  A: 1. Batch Processing Systems: Processed jobs sequentially using punched cards. 2. Time-Sharing Systems: Shared resources among multiple users. 3. Personal Computer OS: Made computing accessible to individuals (e.g., MS- DOS, Windows). 4. Networked Systems: Enabled resource sharing over networks. Q: What is the OS boot process?  A: 1. Power-On Self-Test (POST): Checks hardware functionality. 2. BIOS/UEFI Initialization: Identifies the boot device and initializes hardware. 3. Boot Loader Execution: Loads the OS kernel into memory. 4. Kernel Loading: Initializes system processes. 5. User Space Initialization: Starts applications and services. 6. Login Prompt/GUI: OS is ready for user interaction. Q: What are the types of boot processes?  A: 1. BIOS Boot: Legacy systems use BIOS and the Master Boot Record (MBR). 2. UEFI Boot: Modern systems use UEFI and the GUID Partition Table (GPT). 3. Network Boot (PXE): Boots from a network server. 4. Fast/Hybrid Boot: Combines cold boot with hibernation for faster startup. 5. Secure Boot: Ensures only trusted code runs during the boot process. 6. External Boot: Boots from external devices like USB drives. Q: What is the difference between cold boot and warm boot?  A: o Cold Boot: Starts the computer from a completely powered-off state, initializing hardware from scratch. o Warm Boot: Restarts the computer without powering it off, skipping certain processes for faster booting. Q: What is hibernation? A: Hibernation saves the contents of RAM to a file on the hard drive or SSD, shuts down the system, and restores it to its previous state when powered on, skipping the full boot process. 1. What is an Operating System (OS)? An OS is essential software that acts as an intermediary between computer hardware and applications. It provides key services to enable efficient and user- friendly interaction with the computer. --- 2. What are the basic functions of an Operating System? Process Management: Controls processes, allocates resources, and prevents interference. Memory Management: Allocates memory and prevents processes from accessing each other's memory. File Management: Organizes and manages data on storage devices. Device Management: Handles communication between hardware and applications. User Interface (UI): Enables user interaction through text commands or graphical elements. --- 3. What are the main components of an Operating System? Kernel: Manages hardware resources and provides core services. Device Drivers: Facilitate communication between OS and hardware. File System: Manages data storage and organization. User Interface (CLI & GUI): Provides methods for interacting with the OS. --- 4. What are the types of Operating Systems? Single-user, Single-tasking: Supports one user and one task at a time (e.g., early MS-DOS). Single-user, Multi-tasking: Allows one user to run multiple programs (e.g., modern Windows). Multi-user: Supports multiple users simultaneously (e.g., Unix). Real-Time OS (RTOS): Provides immediate responses, commonly used in embedded systems. --- 5. How have Operating Systems evolved? Batch Processing Systems: Jobs processed sequentially. Time-Sharing Systems: Resources shared among users. Personal Computer OS: Examples include MS-DOS and Windows. Networked Systems: Enabled resource sharing over networks. --- 6. What are the steps in the OS boot process? 1. Power-On Self-Test (POST): Checks essential hardware components. 2. BIOS/UEFI Initialization: Prepares devices and identifies the boot device. 3. Boot Loader Execution: Loads the OS kernel into memory. 4. Kernel Loading: The kernel takes control. 5. Init Processes: Initializes system processes. 6. User Space Initialization: Launches user interfaces and applications. --- 7. What is the difference between Cold Boot and Warm Boot? Cold Boot: Starts the computer from a completely powered-off state. Warm Boot: Restarts the computer without fully powering it off. --- 8. What is Hibernation? Hibernation saves the system's RAM contents to a file on the disk, shuts down the computer, and restores the state when powered on again. --- 9. What are the types of boot processes? BIOS Boot Process: Uses the Master Boot Record (MBR). UEFI Boot Process: Uses GUID Partition Table (GPT) and EFI System Partition (ESP). Network Boot (PXE): Boots the OS from a network server. Fast Boot/Hybrid Boot: Combines cold boot with hibernation for faster startups. Secure Boot: Ensures only trusted OS components run during boot. Boot from External Media: Uses USB or external drives for booting.