1.2 Input Devices

 

1.2 Input Devices

 

Input devices are hardware components of a computer system used to enter data and instructions into the computer. They convert human-readable data into machine-readable form for processing.

 

Examples of Input Devices:

Mouse

Keyboard

Joystick

Microphone

Scanner

Webcam

Touchscreen

Touchpad

 

Mouse

A mouse is a handheld pointing input device used to select and control objects on the computer screen. It is mainly used with GUI-based systems for pointing, clicking, dragging, and scrolling. It has left, right, and scroll buttons.

 

Keyboard

A keyboard is an input device used to enter text, numbers, and commands into a computer by typing. A standard keyboard has 104 keys and the most common layout is QWERTY, named after the first six keys of the top row. Types of Keys on a Keyboard: Alphabet keys: A to Z, Numeric keys: 0 to 9 and mathematical symbols, Function keys: F1 to F12, Cursor movement keys: Arrow keys

Special purpose keys: Enter, Spacebar, Shift, Ctrl, Alt, Delete

 

Joystick

A joystick is an input device mainly used for playing video games and simulation systems. It consists of a movable stick that detects direction and movement and has buttons for game control.

 

Microphone

A microphone is an input device used to enter sound or voice into a computer. It converts sound waves into digital signals and is used for voice recording, online meetings, and video conferencing.

 

Scanner

A scanner is an input device used to convert printed documents or images into digital form. It is commonly used for digitizing text and photographs.

 

Webcam

A webcam is an input device used to capture live images and videos. It is mainly used for video calls, online classes, and video conferencing.

 

Touchscreen

A touchscreen is an input device that allows users to give input by touching the display screen directly. It is commonly used in smartphones, tablets, and ATMs.

 

 

Touchpad

A touchpad is a touch-sensitive pointing input device commonly found on laptops. It is used to control the cursor and works like a mouse.

 

📘 1.2 Input Devices - MCQs

1. Which task is most efficiently performed using a mouse?

A. Typing a document            B. Recording sound    C. Dragging and dropping icons ✅   D. Scanning text

2. The main purpose of a keyboard is to:

A. Capture images                  B. Enter text and commands ✅        C. Record sound            D. Control cursor

3. Function keys on a keyboard are labeled as:

A. A1–A12                              B. Ctrl keys                             C. F1–F12 ✅            D. Arrow keys

4. A joystick is mainly used for:

A. Typing        B. Playing games and simulations ✅  C. Scanning documents       D. Video conferencing

5. A microphone is used to input:

A. Images                               B. Text                                    C. Sound ✅                           D. Video

6. A scanner converts:

A. Digital data into paper                                                       B. Paper documents into digital form ✅
C. Sound into text                                                                   D. Video into images

7. A touchscreen accepts input through:

A. Keyboard only                   B. Mouse only                        C. Touch on screen ✅            D. Voice

8. A touchpad is commonly found in:

A. Desktop computers            B. Printers                               C. Laptops ✅                        D. Servers

9. Which input device does not require physical movement on a surface?

A. Mouse                                B. Touchpad                            C. Joystick                  D. Touchscreen ✅

10. A standard keyboard generally has:

A. 84 keys                               B. 90 keys                               C. 104 keys ✅                       D. 120 keys

11. QWERTY is called so because:

A. It is fastest layout                                                               B. It is the newest layout
C. It is named after first six top-row letters ✅                     D. It is named after inventor

12. Which device is used for video calling as video input?

A. Keyboard                           B. Mouse                                C. Webcam ✅                       D. Scanner

13. Which input device is built into most laptops for cursor control?

A. Joystick                              B. Touchpad ✅                     C. Scanner                  D. Microphone

14. Touchpad performs the same function as a:

A. Keyboard                           B. Mouse ✅                          C. Scanner                  D. Speaker

15. Which of the following is NOT an input device?

A. Mouse                                B. Keyboard                            C. Scanner                  D. Printer ✅

16. Which device acts as both input and output device?

A. Mouse                                B. Keyboard                            C. Touchscreen ✅                 D. Scanner

17. Which input device is MOST suitable for entering hand-drawn pictures into a computer?

A. Mouse                                B. Scanner ✅                        C. Keyboard                D. Webcam

18. Which input device reduces the need for both keyboard and mouse?

A. Touchpad                           B. Scanner                              C. Touchscreen ✅                 D. Joystick

19. Which input device is generally used in laptops instead of an external pointing device?

A. Mouse                                B. Touchpad ✅                     C. Joystick                  D. Scanner

20. Which input device is MOST suitable when a user needs to interact with a computer without using any physical buttons or keys?

A. Mouse                                B. Keyboard                            C. Touchscreen ✅                 D. Scanner

What are input devices? Write any two functions of a mouse.

What is a keyboard? Name any four types of keys found on a keyboard.

What is a joystick? How is a touchpad different from a mouse?

Define a mouse. What is a microphone used for?

What is a scanner? Write two uses of a webcam.

1.1 Introduction to Computer Systems

 

1.1 Introduction to Computer Systems

 

1.1.1 Definition and features of computer system

The word “Computer” comes from the Latin word Computare, which means “to calculate”. A computer is an electronic device that accepts data as input, processes it according to given instructions, stores data and results, and produces meaningful information as output.

Features of a Computer

 

1. Automatic

A computer works automatically once instructions are given through software. Once a program is started, the computer performs tasks automatically without human intervention. Example: Printing 1000 pages continuously without monitoring.

 

2. Speed

A computer system can perform millions of calculations per second. It completes tasks much faster than humans. The table below shows the speed of the computer in different units of time.

Unit of Time	Part of second	Power of 10
Millisecond	1/1000	One Thousand (10-3)
Microsecond	1/1000000	One Millionth (10-6)
Nanosecond	1/1000000000	One Billionth (10-9)
Picosecond	1/1000000000000	One Trillionth (10-12)
Femtosecond	1/1000000000000000	One Quadrillionth (10-15)

 

3. Accuracy

A computer provides accurate results if correct data and instructions are given. Errors occur only due to wrong input or programs. The incorrect output produced due to incorrect input is referred to as Garbage In Garbage Out (GIGO). Errors due to hardware or software faults are called bugs.

 

4. Storage

A computer can store a large amount of data, information, and programs for future use.1 Byte = 1 character.

1 Bit = 1 or 0	4 bits = 1 Nibble
8 bits = 1 Byte	1024 bytes = 1 KB	KB-Kilobyte	EB-Exabyte
1024 KB = 1 MB	1024 MB = 1 GB	MB-Megabyte	ZB-Zettabyte
1024 GB = 1 TB	1024 TB = 1 PB	GB-Gigabyte	YB – Yottabyte
1024 PB = 1 EB	1024 EB = 1 ZB	TB-Terabyte
1024 ZB = 1 YB		PB-Petabyte

 

5. Diligence

A computer can work continuously for a long time without getting tired or losing efficiency. The capability of a computer to perform a task repeatedly without losing speed and accuracy for a long time is known as diligence.

 

6. Versatility

A computer system can perform different types of tasks such as calculations, document creation, internet browsing, and multimedia work. Versatility refers to the capability of doing various kinds of tasks.

 

7. No Intelligence

A computer cannot think or make decisions on its own. It works strictly according to the instructions provided by the user.

 

 

1.1.2 Application Areas of Computer Systems

Computers are very powerful and versatile. They help people work faster, correctly, and more efficiently. With computers, people can prepare documents, spreadsheets, presentations, and graphics. They can also enjoy modern facilities like instant messaging, video chatting, email, online shopping, ticket booking, banking, and getting the latest news. Today, computers are used in almost every field of life. Some important applications are:

 

Education

Computer systems are used in education for teaching and learning purposes. Teachers use computers to prepare teaching materials and presentations, while students use them for learning through the internet, online classes, and educational software. Computers are also used to keep student records and examination results.

 

Communication

Computers play a vital role in communication. They are used to send and receive information through email, video conferencing, chatting, and social media platforms. Computers make communication faster, easier, and global.

 

Entertainment

Computers are used in entertainment for playing games, watching movies, listening to music, animation, and video editing. They provide digital entertainment through multimedia and online platforms.

 

Banking

In the banking sector, computers are used for maintaining customer records, processing transactions, online banking, ATM services, and generating bank statements. Computer systems have increased accuracy, speed, and security in banking services.

 

Medicine and Healthcare

Computer systems are widely used in hospitals and healthcare centers. They are used to maintain patient records, assist in medical diagnosis, operate medical equipment, and manage hospital systems. Computers are also used in medical research.

 

Scientific research

Computers are used in scientific research to analyze large amounts of data, conduct simulations, weather forecasting, and space research. They help scientists perform complex calculations accurately and quickly.

 

Business

In business organizations, computers are used for accounting, billing, payroll processing, inventory management, record keeping, and communication. They help in efficient management and decision making.

 

Agriculture

Computers are used in agriculture for weather forecasting, crop management, data analysis, and modern farming techniques. They help farmers increase productivity and efficiency.

 

Transportation

Computers are used in transportation systems for ticket booking, traffic control, navigation, and managing transport schedules. They help reduce human errors and improve safety.

 

Government Offices

Government offices use computer systems for census data, record keeping, tax systems, e-governance services, and public administration. Computers improve efficiency and transparency in government services.

 

 

1.1.3 Functions of a computer system: Input, Process, Output, Storage (IPOS) with Basic Block Diagram.

 

A computer system performs its work through four basic functions known as the IPOS cycle. IPOS stands for Input, Process, Output, and Storage. These functions work together to convert data into meaningful information.

 

The block diagram of the IPOS cycle of the computer system as:

 

1. Input

Input is the process of entering raw data and instructions into the computer system.
Input devices such as keyboard, mouse, scanner, and microphone are used to provide data to the computer.

 

2. Process

Processing is the operation performed on the input data according to the given instructions.
The CPU (Central Processing Unit) processes data by performing arithmetic and logical operations to convert data into information.

 

3. Output

Output is the result produced after processing the data.
Output devices like monitor, printer, and speaker are used to display or produce the processed information.

 

4. Storage

Storage refers to saving data, programs, and results for future use.
A computer uses primary memory (RAM, ROM) and secondary memory (HDD, SSD, pen drive) to store information.

 

 

1. The word “Computer” is derived from which word? [k]

A. Compute                B. Calculus                 C. Computare ✅                   D. Calculation

2. A computer is best defined as: [k]

A. A mechanical device                      B. An electronic device that processes data ✅
C. A thinking machine                                    D. A communication tool

3. Which feature allows a computer to work without human intervention once started? [k]

A. Speed                     B. Accuracy                C. Automatic ✅                    D. Versatility

4. Performing millions of calculations per second shows which feature? [u]

A. Accuracy                B. Speed ✅               C. Storage                               D. Diligence

5. Wrong output due to wrong input is called: [k]

A. Bug                         B. Virus                       C. GIGO ✅                           D. Malware

6. A computer working continuously for long hours shows: [u]

A. Accuracy                B. Speed                      C. Diligence ✅                     D. Versatility

7. A computer editing videos, calculating results, and browsing the internet shows: [a]

A. Speed                     B. Accuracy                C. Versatility ✅                    D. Storage

8. Which feature proves that a computer cannot think on its own? [k]

A. Speed                     B. Accuracy                C. Automatic                          D. No intelligence ✅

9. Which unit represents one billionth of a second? [k]

A. Microsecond          B. Millisecond            C. Nanosecond ✅                 D. Picosecond

10. Which unit represents one trillionth of a second? [k]

A. Nanosecond           B. Microsecond          C. Picosecond ✅                   D. Femtosecond

11. Sending emails and video calls belongs to: [k]

A. Entertainment        B. Business                 C. Communication ✅           D. Research

12. Online shopping and billing are examples of computer use in: [u]

A. Business ✅          B. Education               C. Agriculture             D. Government

13. Weather forecasting mainly uses computers in: [u]

A. Entertainment        B. Agriculture             C. Communication     D. Scientific research ✅
14. Computers reduce human error most effectively in: [ HA]
A. Entertainment        B. Manual work          C. Automated systems ✅      D. Games

15. IPOS stands for: [K]

A. Input, Program, Output, Storage               B. Input, Process, Output, Storage ✅
C. Instruction, Process, Output, Speed           D. Input, Processing, Object, System

16. Entering data into the computer is called: [K]

A. Processing              B. Output                    C. Input ✅                D. Storage

17. Which device is used for input? [K]

A. Monitor                  B. Printer                    C. Keyboard ✅         D. Speaker

18. Which part processes data in a computer system? [K]

A. Output device        B. CPU ✅                 C. Input device           D. Storage device

19. Arithmetic and logical operations are done by: [U]

A. CU                          B. Register                  C. ALU ✅                 D. ROM

20. The processed result displayed to the user is called: [K]

A. Input                       B. Output ✅              C. Storage                   D. Processing

21. Saving data for future use is called: [K]

A. Input                       B. Processing              C. Output                    D. Storage ✅

22. Which memory is volatile? [U]

A. ROM                      B. HDD                                   C. SSD                        D. RAM ✅

23. Which stage converts data into information? [A]

A. Input                       B. Storage                   C. Processing ✅        D. Output

24. Which statement best explains the term “Garbage In, Garbage Out (GIGO)” in a computer system? [HA]

A. Computer always produces correct output B. Computer can correct wrong input automatically
C. Wrong input leads to wrong output ✅                 D. Computer makes decisions on its own

25. In the basic block diagram of a computer system, which component directly controls and coordinates all operations? [A]

A. Input Unit              B. Output Unit            C. Storage Unit           D. Central Processing Unit (CPU) ✅

 

Short Questions

 

What is computer? Explain why a computer is called an automatic machine.

What is GIGO? How does diligence differentiate a computer from humans?

What is versatility? Explain accuracy as a feature of a computer system.

Why is a computer said to have no intelligence?

Explain the importance of storage in a computer system.

How do computers help farmers in agriculture?

Explain the use of computers in business organizations.

 

Long Questions

 

Draw and Explain the functions of a computer system with reference to the IPOS cycle.

Define a computer system and Explain any five features of a computer system.

Explain the application of computer systems in different fields.

Describe the role of computers in education and communication.

Explain the use of computers in banking and healthcare sectors.

Explain how computers are useful in business and government offices.