Samacheer Kalvi Class 9 Science Solutions Chapter 26 Parts of Computer

In simple words: This table shows the correct pairings for common computer parts and their functions or connection types. Each item from Column A is linked with its matching description from Column B.

🎯 Exam Tip: When matching, carefully consider the primary function or category of each item. For example, a printer's main role is to give output, and Bluetooth is a wireless way to connect.

III. Answer Briefly:

Question 1. Name the parts of a computer.
Answer: The three main parts of a computer that work together are:
1. Input Unit
2. Central Processing Unit (CPU)
3. Output Unit.
These parts allow the computer to take in information, process it, and show results. Each part has a specific job in making the computer work.
In simple words: A computer has three main parts: an input unit to get information, a CPU to think, and an output unit to show results.

🎯 Exam Tip: When listing parts of a system, always try to categorize them (like input, process, output) to show a clear understanding of their roles.

Question 2. Bring out any two differences between input and output devices.
Answer: Here are two differences between input and output devices:
**Input devices**
1. Input units help send data and commands to the computer for processing. This is how we give instructions.
2. Input devices only allow data to be entered into a computer. They are one-way streets for information moving in.
**Output devices**
1. Output units convert the computer's commands (binary signals) into information that we can easily understand, like text or pictures. This makes the computer's work visible.
2. Output devices only receive data output from the computer. They show us the results of the computer's processing.
In simple words: Input devices put information *into* the computer, while output devices take information *out* of the computer to show us.

🎯 Exam Tip: Clearly state the direction of data flow (into or out of the computer) to distinguish between input and output devices.

9th Science Guide Parts of Computer Additional Important Questions and Answers

I. Choose the Correct Answer:

Question 1. .................... plays an important role in a computer as an input device.
(a) Keyboard
(b) Scanner
(c) Printer
(d) Mouse
Answer: (a) Keyboard
In simple words: The keyboard is a main input device that lets you type letters, numbers, and symbols into the computer. It's how you write words on the screen.

🎯 Exam Tip: Keyboards are fundamental for text entry and command input, making them one of the most important input devices.

Question 2. .................... is an essential part of the computer.
(a) Keyboard
(b) CPU
(c) Mouse
(d) Wi-Fi
Answer: (b) CPU
In simple words: The CPU, or Central Processing Unit, is like the brain of the computer. It does all the thinking and calculations that make the computer work.

🎯 Exam Tip: Understand that the CPU is the core component that executes instructions and performs calculations, making it essential for a computer's operation.

Question 3. A bit has a single binary value either .................... or ....................
(a) 1,-1
(b) 0,1
(c) 1,2
(d) 2,0
Answer: (b) 0,1
In simple words: In computer language, a "bit" is the smallest piece of information. It can only be one of two things: a zero (0) or a one (1). This forms the basic building blocks of all digital data.

🎯 Exam Tip: Remember that bits (0s and 1s) are the fundamental units of information in digital computing, representing binary states like on/off or true/false.

Question 4. The personal computer comes under the .................... computer.
(a) mainframe
(b) mini
(c) micro
(d) super
Answer: (c) micro
In simple words: Personal computers, like desktop PCs and laptops, are called microcomputers because they use microprocessors and are designed for individual users. They are smaller than big, powerful computers used by companies.

🎯 Exam Tip: Classify computers based on their size, processing power, and intended use; personal computers fall into the microcomputer category.

Question 5. ....................cable transmits high quality and high bandwidth streams of audio and video.
(a) VGA
(b) USB
(c) Data
(d) HDMI
Answer: (d) HDMI
In simple words: An HDMI cable is a special wire that sends both sound and high-quality video between devices, like from a computer to a TV, all through one cable. This helps to connect modern screens.

🎯 Exam Tip: Recognize HDMI as the standard for high-definition digital audio and video transmission in modern electronics.

Question 6. ....................is used to connect the speaker to the computer.
(a) Audio jack
(b) Power card
(c) Data cable
(d) USB cable
Answer: (a) Audio jack
In simple words: An audio jack is a small port on your computer where you plug in headphones or speakers to hear sounds. It’s specifically for audio signals.

🎯 Exam Tip: Identify the specific port or cable needed for different peripherals; an audio jack is designed solely for sound input/output.

Question 7. ....................cable helps to establish internet connectivity.
(a) Power card
(b) Audio jack
(c) Ethernet
(d) USB
Answer: (c) Ethernet
In simple words: An Ethernet cable is a network cable that connects computers and other devices to the internet or a local network. It provides a fast and stable wired connection.

🎯 Exam Tip: Distinguish Ethernet cables as the primary wired connection for local area networks and internet access, known for their reliability.

II. Answer the Following:

Question 1. What are the input devices?
Answer: Input devices are tools that help us send data and commands to the computer for processing. These devices are used to enter information, instructions, or choices into the computer system. They act as a bridge between the user and the computer. For example, a keyboard is an input device. The devices that are used to enter data are called input devices.
In simple words: Input devices are tools like keyboards or mice that let you put information or commands into a computer.

🎯 Exam Tip: Clearly define input devices by their function of transmitting data from the user or external sources to the CPU for processing.

Question 2. Write some examples of input and output devices of a computer system.
Answer: Here are some examples of input and output devices for a computer system:
**Input devices:**
Keyboard, Mouse, Scanner, Barcode reader, Microphone, Web camera, and Light pen are some common input devices. These devices allow users to feed data and instructions into the computer.
**Output devices:**
Monitor, Printer, Speaker, and Scanner are some common output devices. These devices show or present the processed information from the computer to the user. A scanner can be both an input and output device depending on its type and function.
In simple words: Keyboards and mice are examples of input devices, while monitors and printers are examples of output devices.

🎯 Exam Tip: When listing examples, ensure you provide a balanced selection for both categories to demonstrate comprehensive knowledge.

Question 3. What is Keyboard?
Answer: A keyboard is a very important input device for a computer. It lets you type in letters, numbers, and symbols. The keyboard helps to enter data. It has two main types of keys: number keys for typing numbers and alphabet keys for typing letters. Using a keyboard, you can write documents, send emails, and give commands to the computer. The keys with numbers are called number keys and the keys with letters are called alphabet keys.
In simple words: A keyboard is an input device used for typing letters, numbers, and commands into the computer.

🎯 Exam Tip: Highlight the keyboard's primary function of data entry and its two main categories of keys (alphabet and numeric).

Question 4. Explain CPU.
Answer: CPU stands for Central Processing Unit. It is often called the "brain" of the computer because it performs most of the processing inside. The CPU is made up of three main units that work together:
(i) **Memory Unit:** This part of the computer temporarily saves all data and information. Data size is measured in units called Bits. A Bit has a single binary value, either 0 or 1. We can classify memory units into two types: primary and secondary memory. Memory can also be added from outside using things like Compact Disks (CD) or Pendrives.
(ii) **Arithmetic Logic Unit (ALU):** The ALU performs all mathematical calculations (like addition, subtraction, multiplication, and division) and logic operations. This unit is crucial for solving problems.
(iii) **Control Unit:** This unit acts like a traffic controller, managing and directing all the functions of every part of the computer. It makes sure that everything works in the correct order.
In simple words: The CPU is the computer's brain, made of a memory unit to store data, an ALU to do math, and a control unit to manage everything.

🎯 Exam Tip: Break down the CPU's explanation into its core components (Memory, ALU, Control Unit) and briefly describe each one's primary function.

Question 5. What is Bit?
Answer: A Bit is the smallest unit of data in a computer. It stands for "binary digit". The memory unit in the computer saves all data and information temporarily. A Bit has a single binary value, which can be either 0 or 1. These 0s and 1s are the basic building blocks that computers use to represent all kinds of information, like text, images, and sounds. Every piece of data is ultimately stored as a combination of these bits.
In simple words: A bit is the smallest unit of computer data, which is either a 0 or a 1.

🎯 Exam Tip: Define "bit" clearly as the fundamental binary unit (0 or 1) and explain its role in representing all digital information.

Question 6. What are the types of monitors?
Answer: There are two main types of monitors commonly used:
1. **Cathode Ray Tube (CRT) monitors:** These are older, bulky monitors that use a large vacuum tube to display images. They were very common in the past but are rarely used now.
2. **Thin Film Transistor (TFT) monitors:** These are modern, flat-panel displays, also known as LCD (Liquid Crystal Display) monitors. They are thin, light, and use less power than CRT monitors. Most computer screens today are TFT monitors.
Monitors are essential output devices that show visual information from the computer.
In simple words: The two main types of monitors are older, bulky CRT monitors and newer, flat TFT (LCD) monitors.

🎯 Exam Tip: When describing monitor types, include a key characteristic for each (e.g., "bulky" for CRT, "flat-panel" for TFT).

Question 7. What is the classification of the computer?
Answer: Computers can be classified in many ways based on different factors. Here's how computers are generally grouped:
The computers can be classified as follows based on their design, shape, speed, efficiency, how their memory unit works, and their typical applications:
• Mainframe Computer
• Mini Computer
• Micro or personal computer
• Supercomputer
Each type serves different purposes, from basic personal use to complex scientific research.
In simple words: Computers are grouped into types like mainframe, mini, micro (personal), and supercomputers based on how they are designed, how fast they are, and what they are used for.

🎯 Exam Tip: List the main categories of computers and briefly mention the criteria (size, power, application) used for their classification.

Question 8. Explain the types of cables.
Answer: Many types of cables are used to connect different parts of a computer system. Here are some common ones:
• **Video Graphics Array (VGA) Cable:** This cable connects the computer monitor to the CPU. It transmits analog video signals.
• **High Definition Multimedia Interface (HDMI) Cable:** An HDMI cable sends high-quality and high-bandwidth streams of both audio and video. It is commonly used to connect a monitor or projector to the computer.
• **Universal Serial Bus (USB) Cable/Cord:** Devices like printers, pen drives, scanners, mice, keyboards, web cameras, and mobile phones are connected to the computer using a USB cord or cable. USB is very versatile for data transfer and power.
• **Data Cable:** A data cable specifically transmits data and is used to connect a tablet or mobile phone to the CPU for transferring files.
• **Power Cord:** A power cord temporarily connects an electronic device, such as a computer, to the main electricity supply. This provides the necessary power for the device to operate.
• **Audio Jack:** The audio jack is a connector used to plug in speakers or headphones to the computer to output sound.
• **Mic Cable:** A microphone wire or cord is used to connect a microphone to the CPU, allowing for audio input.
In simple words: Cables like VGA, HDMI, and USB connect computer parts or devices. VGA is for older video, HDMI is for good video and sound, and USB is for many different devices. Other cables like power cords and audio jacks help the computer work.

🎯 Exam Tip: For each cable type, specify its main purpose and what it typically connects, focusing on its unique function.

Question 9. Explain wireless connections.
Answer: Wireless connections allow devices to communicate and transfer data without using physical cables. Instead, they use radio waves or infrared signals. Two common types of wireless connections are Bluetooth and Wi-Fi.
• **Bluetooth:** This technology allows devices like mice, keyboards, and speakers to connect to the computer wirelessly over short distances. Bluetooth also enables data sharing between nearby devices, making it convenient for close-range connections.
• **Wi-Fi:** Wi-Fi provides net connectivity without any physical connecting cables. It allows devices to connect to the internet and share data from anywhere within the network's range. Wi-Fi uses radio signals to create a wireless local area network, providing freedom of movement.
Wireless connections offer flexibility and convenience, but they can sometimes be slower than wired connections.
In simple words: Wireless connections, like Bluetooth and Wi-Fi, let devices talk to each other without wires. Bluetooth is for nearby devices, and Wi-Fi connects devices to the internet.

🎯 Exam Tip: When explaining wireless connections, describe how they work (using radio waves) and give key examples like Bluetooth and Wi-Fi, outlining their primary uses.