by Tiwari Academy
NCERT Solutions for Class 2 Computer Science Chapter 4 Input Devices Processing and Output Devices updated and modified for new session 2024-25. Students of class 2 will learn here about input devices, processing units and output devices.
Class 2 Computer Science 4 Input and Output Devices Question Answers
Processing Units
Computer works on given data and commands. These data and commands are given to the computer through the keyboard and mouse. The keyboard and the mouse are called input devices. The computer processes the input data. Input device passes on these instructions to the processing unit. After processing the data in CPU, the output is shown on the monitor or printer.
There are some basic skills and techniques for using a computer.
First you have to be familiar with keyboard, mouse and monitor.
You must learn some mouse actions.
Remember the keys on the keyboard.
Learn how to switch the computer “ON” and “OFF”.
Also learn about using storage devices like floppy disk, hard disk and CD.
Input, Processing, Output, Storage
The above four words summarize the operations of a computer.
Input: The work and instructions we feed in a computer are called input. The information about this work is also called “data”. We use a keyboard and mouse to feed instructions and data.
Example : Solve : 3 + 5 + 2
In this example 3, 5, 2 is data.
“ADD” (+) is instruction.
So keyboard and mouse are input devices.
Output: After process of any work or job given to a computer, its result will be shown on a monitor or on a paper through a printer. The result after processing is called output.
Solve : 3 + 5 + 2 Data : 3, 5, 2 Instruction : “ADD” (+)
Process : 3+5+2 Output : 10
Monitor and printer are output devices.
Processing and Storage
Processing: The processing function is performed by the “CPU” (Central Processing Unit). This electronic device is mounted on a large board called motherboard or main board inside the casing.
Like us computers do have memory. The computer’s memory is called RAM. Information on “RAM” is lost when you turn off the computer, or the power.
Storage: Music or play, stored in a cassette can be played in a tape-recorder. Games, instructions or programs are stored in floppy disks, hard disks and CDs. We run or play these disks in disk drives which are just like a tape recorder.
Some other Input Devices
We know that keyboard and mouse are the most popular input devices. These are attached to every computer.
Through these devices, the raw data and instructions are fed (input) into the computer.
There are some other ways that you can get data into your computer.
Scanner
It is used to input texts and pictures into computer. It is generally used to store photographs or paintings directly into the computer.
A Barcode Scanner is used to read the prices of items which is printed in the form of bars on items. It helps in keeping record of the items sold. It is used in shopping malls and big shops.
Microphone
It is used to input or feed our voice or any other sound into the computer.
Joystick
In a joystick, a lever or handle is attached to the tracking ball which rotates within a fixed base.
The pointer on screen moves in direction of movement of handle. It is used in playing games on computer.
Trace ball
It is a pointing device which is used to control the movement of a moving object on the screen by rolling the ball with fingers. It is used for games.
Touch Screen
The Touch Screen is a touch sensitive screen on monitor. We can feed a value into computer by simply touching it on the screen.
