By the end of this chapter you'll be able to…

  • 1Name the three parts of the CPU
  • 2Differentiate input and output devices
  • 3Explain how memory is expanded
  • 4Identify the VGA and Ethernet cables
  • 5Recall wireless connections
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Why this chapter matters
Parts of Computer builds digital literacy — knowing the CPU, devices and connections. The CPU's parts, input/output devices and cables are directly tested book-back content in the TN Class 6 Term 2 exam.

Before you start — revise these

A 5-minute refresher here will save you 30 minutes of confusion below.

Parts of Computer — Class 6 Science (Samacheer Kalvi)

TN State Board (Samacheer Kalvi) Class 6 Science, Term 2 — Chapter 7 (Computer Science). Inside and around the computer.


1. About this chapter

This chapter covers the CPU, input and output devices, memory, and connections (cables and wireless).

2. The CPU and memory

  • The CPU (Central Processing Unit) is the "brain" of the computer. It has three parts: the Arithmetic and Logic Unit (ALU), the Control Unit (CU) and the Memory Unit.
  • The memory unit stores data and information. Memory can be expanded externally with a compact disc (CD) (or a pen drive).

3. Input and output devices

  • Input devices send data into the computer — keyboard, mouse, scanner. The mouse moves the pointer on the screen; the scroll ball/wheel moves a page up and down.
  • Output devices give out results — monitor, printer, speaker, scanner. A speaker is an output device.

4. Connections

  • A VGA cable connects the CPU to the monitor; an Ethernet cable provides internet connectivity.
  • Wireless connections (no cables) include Wi-Fi and Bluetooth.

5. Worked examples

Example 1. Which device moves the pointer on the screen? The mouse.

Example 2. Name an output device. A speaker (also monitor, printer).

Example 3. Which cable connects the CPU to the monitor? The VGA cable.

6. Book-back questions (Samacheer Kalvi)

I. Choose the correct answer

  1. The device used to move the pointer on the screen is the — (a) keyboard / (b) mouse. Ans: (b) mouse.
  2. The page on the monitor is moved up and down using the — (a) scroll ball/wheel / (b) left button. Ans: (a) scroll ball.
  3. Memory can be expanded externally with the help of a — (a) compact disc / (b) mouse. Ans: (a) compact disc.
  4. An output device among these is the — (a) mouse / (b) speaker. Ans: (b) speaker.
  5. The cable that connects the CPU to the monitor is the — (a) USB / (b) VGA cable. Ans: (b) VGA cable.
  6. An example of a wireless connection is — (a) Wi-Fi / (b) VGA. Ans: (a) Wi-Fi.

II. Fill in the blanks 7. The three parts of the CPU are the ALU, the control unit and the memory unit. 8. The keyboard is an input device. 9. Ethernet cable helps to establish internet connectivity.

III. Answer briefly 10. Name two output devices. — A monitor and a printer (also speaker, scanner). 11. Name two wireless ways to connect to the internet. — Wi-Fi and Bluetooth.

7. Common mistakes

  • Mistake: Calling a speaker an input device. Fix: A speaker is an output device; the keyboard and mouse are input.
  • Mistake: Saying the CPU has two parts. Fix: The CPU has three parts — ALU, control unit and memory unit.
  • Mistake: Mixing up VGA and Ethernet cables. Fix: VGA connects the CPU to the monitor; Ethernet connects to the internet.

8. Quick revision

  • Term 2 · Ch 7 · parts of computer.
  • CPU (brain) = ALU + control unit + memory unit; memory expanded with a CD/pen drive.
  • Input: keyboard, mouse (moves pointer), scanner; output: monitor, printer, speaker.
  • VGA cable = CPU to monitor; Ethernet = internet; Wi-Fi and Bluetooth = wireless.

Key formulas & results

Everything you need to memorise, in one card. Screenshot this for revision.

CPU
ALU + control unit + memory unit
The brain of the computer.
Devices
input: keyboard, mouse, scanner; output: monitor, printer, speaker
Mouse moves the pointer.
Memory expansion
compact disc (CD) or pen drive
External storage.
Connections
VGA (CPU-monitor), Ethernet (internet), Wi-Fi/Bluetooth (wireless)
Wired and wireless.
⚠️

Common mistakes & fixes

These are the exact errors that cost students marks in board exams. Read them once, save yourself the trouble.

WATCH OUT
Calling a speaker an input device
A speaker is an output device; the keyboard and mouse are input.
WATCH OUT
Saying the CPU has two parts
The CPU has three parts — ALU, control unit and memory unit.
WATCH OUT
Mixing up VGA and Ethernet cables
VGA connects the CPU to the monitor; Ethernet connects to the internet.

Practice problems

Try each one yourself before tapping "Show solution". Active recall > rereading.

Q1EASY· MCQ
The device used to move the pointer on the screen is the ____.
Show solution
mouse.
Q2EASY· MCQ
An output device among these is the ____ (mouse / speaker).
Show solution
speaker.
Q3EASY· MCQ
The cable that connects the CPU to the monitor is the ____.
Show solution
VGA cable.
Q4EASY· Fill in the blanks
Memory can be expanded externally with the help of a ____.
Show solution
compact disc (CD).
Q5EASY· Fill in the blanks
The three parts of the CPU are the ALU, the ____ and the memory unit.
Show solution
control unit.
Q6EASY· Answer briefly
Name two wireless ways to connect to the internet.
Show solution
Wi-Fi and Bluetooth.

5-minute revision

The whole chapter, distilled. Read this the night before the exam.

  • Term 2 Chapter 7 of Samacheer Kalvi Class 6 Science (Computer Science).
  • The CPU is the brain of the computer with three parts: ALU, control unit and memory unit.
  • Memory can be expanded externally with a compact disc or pen drive.
  • Input devices: keyboard, mouse (moves the pointer), scanner; output devices: monitor, printer, speaker.
  • A VGA cable connects the CPU to the monitor; an Ethernet cable gives internet connectivity.
  • Wi-Fi and Bluetooth are wireless connections.

Tamil Nadu (TNBSE) marks blueprint

Where the marks come from in this chapter — so you can plan your prep.

Typical chapter weightage: 3-6 marks across book-back MCQ and short answers

Question typeMarks eachTypical countWhat it tests
MCQ / Fill15-7CPU, devices, cables
Short Answer21Output devices, wireless
Prep strategy
  • Remember the three CPU parts
  • Sort devices into input and output
  • Match each cable to its use
  • Recall Wi-Fi and Bluetooth as wireless

Where this shows up in the real world

This chapter isn't just an exam topic — it lives in the world around you.

Using computers

Knowing the parts helps operate a computer well.

Connectivity

Cables and Wi-Fi link devices and the internet.

Storage

CDs and pen drives expand memory.

Exam strategy

Battle-tested tips from teachers and toppers for this chapter.

  1. List the three CPU parts
  2. Sort devices into input and output
  3. Pair each cable with its use
  4. Name Wi-Fi and Bluetooth as wireless

Going beyond the textbook

For olympiad aspirants and curious learners — topics that build on this chapter.

  • Classify ten devices as input or output.
  • Explain the path of data from the keyboard to the monitor.

Where else this chapter is tested

CBSE board isn't the only one — other exams test this chapter too.

TN Class 6 Term 2 ExamMedium
Computer / ICT testsMedium
School unit testsHigh

Questions students ask

The real ones — pulled from the Q&A community and tutor sessions.

An input device sends data into the computer (like a keyboard or mouse), while an output device gives out results from the computer (like a monitor, printer or speaker).

The CPU has the Arithmetic and Logic Unit (ALU) that does calculations, the Control Unit that directs the work, and the Memory Unit that stores data.
Verified by the tuition.in editorial team
Last reviewed on 4 June 2026. Written and reviewed by subject-matter experts — read about our process.
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