Lesson 2 Q/A(Eng. Medium)

 Q:1  How many classes have been divided into computers in modern times.

Ans:- Computers are categorized into several classes based on their purpose and principles of operation. Purpose-wise, they are divided into:

1. Special-purpose Computers: Designed for specific tasks with permanent instructions, they excel in efficiency for those tasks but lack versatility. 
2. General-purpose Computers: Capable of running various programs and handling a broad range of applications, these computers are highly versatile. 

Principle of Operation-wise, computers are classified as:

1. Analog Computers: Use continuous physical quantities to represent data. They are useful for real-time simulations but have limited precision.
2. Digital Computers: Represent data in binary form (0s and 1s) and are prevalent in modern computing for their precision and flexibility.
3. Hybrid Computers: Combine features of both antilog and digital computers, suitable for tasks requiring both types of processing.

Digital computers further include:

1. Microcomputers: Small, versatile computers built around microprocessors, widely used today.
2. Minicomputers: Intermediate-sized computers used for specific departmental tasks in organizations.
3. Mainframe Computers: Large, powerful systems used for extensive data processing and reliable, high-capacity tasks.
4. Supercomputers: Extremely powerful and expensive machines used for complex simulations and research, often employing large arrays of processors.

Q 2= How many types of computers are based on the application? explains with examples.

Ans:- Based on their application, computers are classified into two main types: 

1. Special-purpose Computers
2. General-purpose Computers

Special-purpose Computers: These are designed to perform specific tasks with permanently stored instructions. They are efficient for their designated functions but lack flexibility. Examples include:

• ATM Machines: Built specifically for processing financial transactions.
• Digital Watches: Programmed to track time and manage alarms but not for general computing.

General-purpose Computers: These can execute a variety of programs and handle multiple tasks. They are versatile and adaptable to numerous applications. Examples include:

• Personal Computers (PCs): Used for diverse activities such as word processing, gaming, and internet browsing.
• Laptops: Portable devices capable of performing a wide range of computing tasks similar to desktop PCs.

Special-purpose computers excel in efficiency for specific tasks, whereas general-purpose computers offer broad functionality and adaptability.

Q 3 = What is CPU ? discribe its main units.

Ans:- The Central Processing Unit (CPU) is crucial to a computer system, often likened to the brain of the computer. It manages and controls all functions, including data processing, storage, and output.

The CPU comprises three main units:

1. Arithmetic Logic Unit (ALU): The ALU performs all arithmetic (e.g., addition, subtraction) and logic operations (e.g., comparisons). It processes data and executes instructions as directed by the control unit.
2. Control Unit (CU): The CU orchestrates the operations of the CPU by fetching, decoding, and executing instructions. It directs data flow between the CPU, memory, and input/output devices, ensuring all components work together efficiently.
3. Memory: This includes registers and cache within the CPU where data and instructions are temporarily held during processing. Memory ensures that the CPU has quick access to the data needed for operations and stores results after processing.

Together, these components enable the CPU to perform complex tasks and drive the overall functionality of the computer system.

Q 4 = What is general and purpose purpose computers? discribe it.

Ans :- General-purpose computers and special-purpose computers are two categories based on their intended applications and versatility:

General-purpose Computers:

Description: General-purpose computers are designed to handle a wide range of tasks and applications. They are versatile and can run various types of software for different functions.

Characteristics: These computers use software programs to perform a variety of tasks, such as word processing, internet browsing, gaming, and data analysis. They are not pre-programmed for a single specific task but can be adapted to many uses.

Examples: Personal Computers (PCs): Used for everyday tasks like emailing, document creation, and web browsing.

Laptops: Portable versions of PCs that offer similar functionalities and can be used in various settings.

Special-purpose Computers:

Description: Special-purpose computers are designed to perform specific tasks or applications with high efficiency. Their functions are predefined and they are optimized for particular jobs.

Characteristics: These computers have instructions permanently embedded for specific tasks, making them highly efficient in their designated role but not versatile for other functions.

Examples: ATM Machines: Engineered to handle financial transactions and manage banking operations.

Embedded Systems: Found in devices like washing machines and microwave ovens, programmed to control and manage specific functions within those devices.

Q 5= Explain all types of digital computers.

Ans:- Digital computers are categorized based on their size, speed, and capability. They include:

1. Microcomputers: These are small computers with a microprocessor chip at their core, designed for personal use. They include personal computers and laptops, which have evolved from early models like the Altair and Intel 4004. Modern microcomputers offer substantial processing power and are used for a wide range of applications, from everyday tasks to complex data processing.
2. Minicomputers: Introduced in the mid-1960s, minicomputers are mid-sized systems used for specific tasks within organizations. They were smaller and less expensive than mainframes, making them suitable for departmental use. Notable examples include the DEC PDP series, which were used in various applications from industrial control to academic research.
3. Mainframe Computers: Large and powerful, mainframes are used by corporations and research labs for extensive data processing and storage. They were the primary computing resource for large organizations in the past, with examples like the IBM S/360. Mainframes are still used today as servers for high-capacity data and multi-user environments.
4. Supercomputers: These are the most powerful and expensive computers, designed for high-priority tasks such as complex simulations and scientific research. Examples include the CRAY series and India's PARAM supercomputers. They use large arrays of processors working in parallel to perform massive computations.

Q 6= What is keyboard ? Explain different types of keys.

Ans :- A keyboard is an input device used to enter data into a computer or other digital devices. It consists of a set of keys or buttons arranged in a specific layout, primarily designed to input text and commands. Keyboards are essential for typing, executing commands, and interacting with software.

Types of keys on a keyboard include:

1. Alphanumeric Keys: These include letters (A-Z) and numbers (0-9) used for typing text and numerical data.
2. Enter and Escape Keys: The Enter key submits commands or confirms actions, while the Escape key cancels or exits operations.
3. Function Keys: Located at the top of the keyboard (F1-F12), these keys perform specific functions, such as opening help menus or executing program-specific commands.
4. Control Keys: Includes keys like Ctrl, Alt, and Shift, which modify the input of other keys to perform various functions and shortcuts.
5. Navigation Keys: Arrow keys and keys like Home, End, Page Up, and Page Down navigate through text and documents.
6. Modifier Keys: These include Shift, Ctrl, and Alt, which alter the output of other keys or perform special functions when combined.

Q 7= What is printer? Explain all the printers. 

Ans:- A printer is a peripheral device that produces hard copies of digital documents and images on paper. It is widely used in various settings like schools, offices, and banks for printing reports, tickets, and bills. Printers are categorized into two main types: impact and non-impact.

Impact Printers:

1. Dot Matrix Printer: Uses pins striking an ink ribbon to form characters on paper. Although they are outdated for high-quality prints, they excel at creating multiple copies simultaneously, making them useful for multipart forms.
2. Daisy Wheel Printer: Operates similarly to a ball-head typewriter, where a rotating wheel with raised characters impacts an ink ribbon to print text. It is known for producing letter-quality output but is slow and noisy, and cannot print graphics.

Non-Impact Printers:

1. Inkjet Printer: Sprays tiny droplets of ink onto paper to create images and text. Capable of high-resolution colour prints, it is versatile and often combines with scanning and copying functions.
2. Laser Printer: Uses a laser beam and electrostatic charges to transfer toner onto paper. Known for its high-speed, precision, and clarity, it produces sharp text and images with resolutions of 600 dpi or more.

Q =8 Describe the key types of memory with examples.

Ans:- Memory in a computer system is categorized into primary (main) memory and secondary (external) memory, each serving distinct roles.

Primary Memory:

1. Read-Only Memory (ROM): ROM stores critical startup instructions that remain fixed and unchangeable. It retains data even when the power is off, making it non-volatile. For example, the BIOS in a computer is stored in ROM.
2. Random Access Memory (RAM): RAM provides temporary storage for data and instructions that the CPU needs while processing. It is volatile, meaning data is lost when power is turned off. For instance, when you open an application, it loads into RAM for faster access.

Secondary Memory:

1. Floppy Disk: A portable, magnetic storage medium with limited capacity and slower access speeds compared to modern devices. It’s useful for small data transfers.
2. Hard Disk Drive (HDD): A non-volatile storage device with high capacity for long-term data storage, such as operating systems and software. It retains data without power.
3. Compact Disc (CD): A polycarbonate disc used for storing data and music. CDs are read-only, meaning data cannot be modified once written.
4. Digital Versatile Disc (DVD): An optical disc with higher capacity than CDs, used for video and large data storage. DVDs can hold between 4.7GB and 17GB of data.
5. Flash Drive: A portable USB device for data storage with no moving parts. It offers convenience and durability for transferring files between computers.

Q =9. What is computer system? Describe the structure of the computer.

Ans:- A computer system is an integrated set of components that work together to process data and execute instructions. Its basic structure comprises three main units:

Input Unit: This unit captures data and instructions from external sources. Examples include keyboards, mice, and scanners. These devices convert user input into a form that the computer can process.

Central Processing Unit (CPU): The CPU is the core of the computer, acting as its brain. It has three main parts:

1. Arithmetic Logic Unit (ALU): Performs mathematical and logical operations.
2. Control Unit (CU): Directs operations by decoding instructions and managing data flow.
3. Memory: Temporary storage for instructions and data, which includes Random Access Memory (RAM) for volatile storage and Read-Only Memory (ROM) for non-volatile storage.

Output Unit: This unit delivers processed information to users. Devices like monitors, printers, and speakers are used to display or produce the results of computer operations.

Together, these units allow a computer to input, process, and output data efficiently.

Q = 10. Name the input devices of a PC and explain their function in brief.

Ans :- Input devices are essential components of a PC that allow users to interact with and provide data to the computer. Here are some common input devices and their functions:

1. Keyboard: A primary input device used for typing text, numbers, and commands. It consists of keys that represent letters, numbers, and special functions. Users input data and commands via keystrokes.
2. Mouse: A pointing device that allows users to interact with the graphical user interface (GUI) of a computer. It typically has two buttons (left and right) and a scroll wheel, used for selecting and manipulating objects on the screen.
3. Scanner: Converts physical documents and images into digital format. Scanners can be used to digitize photos, text, and graphics, making them editable and shareable on a computer.
4. Microphone: Captures audio input, such as voice or music, and converts it into digital data for processing, recording, or communication.
5. Webcam: Captures video and still images, allowing for video conferencing, live streaming, and recording.

These devices facilitate data entry and interaction, enhancing the overall functionality of a PC.

SHORT ANSWER TYPE QUESTIONS

1. What is input unit and output unit?

Ans:- Input Unit: The input unit of a computer receives and converts user data and commands into a format the computer can process. Examples include keyboards, mice, and scanners.

Output Unit: The output unit converts processed data into a human-readable form, such as displaying on monitors or printing on paper. Examples include monitors, printers, and speakers.

2. What is volatile memory?

Ans:- Volatile memory is a type of computer memory that loses its stored data when power is lost or turned off. It is used for temporary storage of data that the CPU needs quickly, such as RAM (Random Access Memory). It requires constant power to retain information.

3. What is the use of memory in computer?

Ans:- Memory in a computer helps store and quickly access data and instructions needed for running programs. It includes RAM for temporary storage while you work and ROM for permanent instructions, ensuring that the computer operates smoothly and efficiently.

4. What is the difference between Analog Computer and Digital computer?

Ans:- Analog computers process continuous data, like electrical signals or physical measurements, and are used for real-time simulations. Digital computers handle discrete data in binary form, performing calculations and logical operations, and are used for general computing tasks. Analog is for analog signals; digital is for digital data.

5. What is portable computer?

Ans:- A portable computer is a compact, lightweight device designed for easy transport and use on the go. It includes laptops, tablets, and notebooks. These devices feature built-in batteries, allowing them to operate without being plugged into a power source, making them ideal for mobile computing.

6.What is mouse? Explain all types of mouse.

Ans:- A mouse is a computer input device used to control the cursor on a screen. Types include:

1. Optical Mouse: Uses light to detect movement.
2. Laser Mouse: Uses laser for more precision.
3. Wireless Mouse: Connects via radio waves or Bluetooth.
4. Trackball Mouse: Has a stationary ball to control movement.

7. Write a comparative description of Mini and Mainframe computers.

Ans:-Mini computers are mid-sized, suitable for small to medium-sized businesses, offering moderate processing power and multi-user capabilities. Mainframe computers, however, are larger, more powerful, and handle massive data processing for large organizations. Mainframes support many simultaneous users and complex tasks, while minis serve fewer users with less processing power.

8. What is Inkjet and Laser printer?

Ans:- Inkjet Printer: Uses tiny nozzles to spray liquid ink onto paper, creating high-quality color prints and detailed images. Laser Printer: Uses toner powder and a laser beam to transfer text and images onto paper, providing fast, precise, and high-volume printing with sharp text quality.

9. Explain the functioning of Dot Matrix and Daisy wheel printer.

Ans:- Dot Matrix Printer: Prints by striking an ink-soaked ribbon against paper through tiny pins, forming text with dots.

Daisy Wheel Printer: Uses a spinning wheel with pre-formed characters, striking the ribbon onto paper to print one character at a time. Dot matrix is versatile; daisy wheel offers high-quality text.

10. Explain any one input device.

Ans:- A keyboard is an input device used to type text and commands into a computer. It features a set of keys including letters, numbers, and symbols, each corresponding to different functions. Pressing a key sends a signal to the computer to perform specific actions or input data.

11. What is MICR? Write its applications.

Ans:- MICR (Magnetic Ink Character Recognition) uses special magnetic ink to read and process characters on documents, mainly checks. Its applications include automating check processing, reducing fraud, and speeding up data entry in banking and financial systems. MICR technology ensures accurate, efficient handling of financial transactions.

12. What do you mean by Primary and Secondary memory?

Ans:- Primary memory (RAM) is the computer's quick-access storage for actively used data and programs. Secondary memory (HDD, SSD) provides long-term storage for files and software, retaining data even when the computer is off. Primary memory is fast but temporary, while secondary memory is slower but permanent.