Computer Science for Class 2

Computers around us

1.     What is a computer?

           A computer is an electronic machine. It works on electricity.

2.     Which Computer do you have in your school Lab?

          We have Desktop Computers in our school lab.

3.     Name some activities that you like to do most on computers?

           Drawing Picture, Watching Cartoon, Listen to music, Learn, Write, Solve Math             Sums  etc.

4.     Write differences between a computer and a human being.

·        A computer is very fast in doing calculations but a human being is slow in doing calculations.

·        A Computer has no feelings but a human being has feelings.

·        A computer never gets tired but a human being gets tired after some time.

·        A computer does not make mistakes but a human being makes a mistake.

·        A computer cannot take decisions but a human being can take decisions.

Computers make our work easier.

Computers are used in schools, offices, railway stations, airports, banks, super markets, hospitals, homes, animation, photography, etc.

Desktop Computer is a medium-sized computer and is kept on a desk to work.

Laptop is a portable computer and can fit on your lap. It can be carried while travelling and can also work on a battery. It looks like a briefcase.

A tablet computer is a mobile like computer.

A smartphone is a mobile phone which has new features in it.

PC is a Personal Computer.

Parts of a computer

VDU is Visual Display Unit which looks like a TV screen.

CPU is Central Processing Unit that controls all the functions of a computer.

Printer prints your work on paper.

Speaker is used to hear sound or music.

Microphone is used to record sound.

UPS is Uninterrupted Power Supply that keeps the computer ON for some time when there is no electricity.

CD is Compact Disk.

DVD Digital Versatile Disc.

ATM Automated Teller Machine .

A computer mainly consists of four main parts: CPU, Monitor, Keyboard and Mouse.

A monitor looks like a TV Screen. It is used to see cartoon movies or whatever you type.

A computer thinks with its CPU.

A Keyboard is used to type information into a computer.

Mouse is a pointing device. It makes our work easy on a computer.

Printer is used to print your work on paper.

Speakers and Headphones are used to listen to music or recorded sound.

Microphone is used to record sound.

UPS keeps the computer ON even when there I no electricity.

CD ROMs and DVDs store your information.

Keyboard

A Keyboard consists of different types of keys like alphabet keys, number keys, function keys and special character keys.

There are 26 Alphabet keys, 10 Number keys, 2 shift keys and 12 Function Keys on the key board.

Enter key takes the cursor to the next line.

Spacebar Key inserts blank space between words. Spacebar is the longest key on the keyboard.

Backspace key erases the character typed on the left side of the cursor.

Delete key erases the character typed on the right side of the cursor.

Backspace key and delete key helps you in erasing your mistakes on the screen. 

Cursor is a small blinking line on the monitor of a computer.

Caps Lock when ON: you can type capital alphabets.

Num lock Key when ON: you can type numbers using numeric keypad. Num Lock key is used to use numeric keypad.     

Shift Key when pressed, causes a typed letter to appear in upper case; the upper symbol of the number key or symbol key are also typed with its help.

There are Four Arrow keys on the keyboard to move the cursor left, right, up and down .Arrow keys are also called cursor control keys.

Using a computer

Starting a Computer:

Step 1: Switch ON the main power switch.

Step 2: Switch ON the UPS.

Step 3: Switch ON the CPU.

Step 4: Switch ON the monitor.

Shutting Down a Computer:

Step 1: Click the start button. Start menu appears.

Step 2: Click the shutdown button. The windows show shutting down message on the screen.

Step 3: Switch off monitor.

Step 4: Switch off the UPS.

Step 5: Switch off the main power switch.

Step 6: You should also put dust covers on the computer.

Desktop is the first screen that appears after switching ON the computer.

Icons are the small pictures on the desktop.

Start Button is present on the bottom left corner of the screen.

The thin bar at the bottom of the desktop is called taskbar.

Uses of Computers

Computers are used in,

Office for typing and printing the documents , etc.

Schools for making Timetable, Question paper , preparing result ..etc.

Homes to listen music and watch movies ..etc

Railway stations, airport and Bus Deport to book tickets.   

Introduction to MS-Paint

To open paint, Click Start > All Programs > Accessories > Paint

Line tool is used to draw straight lines.

Rectangle tool is used to draw rectangles and squares

Ellipse tool is used to draw ovals and circles.

Fill with color tool fills the color in a closed area.

To do freehand drawing use Pencil Tool.

Eraser is used to erase any part of your drawing.

Paint is a program to draw and color pictures.

Tools group consists of tools to draw and paint various shapes drawings.

Shapes group consists of different shape styles.

Drawing area is the working area.

Colors group consists of various colors to paint your picture with.

  

Abbreviations:

·        PC: Personal Computer.

·        VDU: Visual Display Unit

·        CPU: Central Processing Unit

·        UPS: Uninterrupted Power Supply  

·        CD: Compact Disk.

·        DVD: Digital Versatile Disc.

·        ATM: Automated Teller Machine.

Computer Etiquette:

·        Do not make noise in a computer lab.

·        Always follow the instructions given by teacher.

·        Always keep the CDs in the CD cover.

·        Do not touch the wires when the computer is ON.

·        Always press the keys on the keyboard gently.

·        Do not sit too close to the monitor. It harms your eyes.

·        Always sit straight on chair in front of the computer system.

·        Do not eat or drink in the computer room. 

Arrange the jumbled words:

1.     ALTPOP

2.     DSTEKOP

3.     PCOUMETR

4.     PUC

5.     SUHTODWN

6.     TSRAT

7.     SPU

8.     PCU

9.     ISWTHC

10.  EPNICL

11.   REAESR

12.   LNIE

13.   EILLPES

14.  TERCAGNLE

Answers:  1.Laptop 2.desktop 3.computer 4.CPU 5.Shutdown 6.Start 7.UPS 8.CPU 9.Switch 10. Pencil 11.Eraser 12.Line 13.Eillpes 14. Rectangle  

Answer the following questions.

1.     Name the device used to take printouts.

Ans: Printer

2.     Name the device which thinks for the computer.

Ans: CPU

3.     Name the pointing device which shows the arrow on the screen.

Ans: Mouse

4.     Which key is used to insert blank spaces between words?

Ans: Spacebar

5.     Which keys shows the direction of the cursor?

Ans: Cursor control keys.

6.     Which key is used to type the capital or upper case letter?

Ans: Caps Lock Key when ON or Shift Key.

7.     Name three things that you see on a desktop.

Ans:   Icons

           Start Button

           Taskbar

8.     Name the screen that appears after switching on the computer.

Ans: Desktop

9.     Name any one Icon present on the desktop.

Ans: Recycle Bin

10.  Who uses computers to diagnose the diseases?

Ans:  Computer helps in diagnosing many diseases in Hospital.

11.  Write name of your two favorite cartoons.

Ans: Chota Bheem and Doraemon.

12.  Which machine is used to withdraw money in a bank?

Ans: ATM in bank helps to withdraw money.

13. Write two things that you like to do most on computers.

Ans: I like to do (i) Drawing and (ii) watching cartoon.

14.  How to start Paint?

Ans: Click Start Button > All Programs > Click Accessories > Click Paint

15. Which Tool is used to fill color in drawing?

Ans: Fill with color tool is used to color in drawing.

16. Which Tool is used to draw squares?

Ans: To draw Square we can use Rectangle tool with pressing and holding the shift key.