Class 9 Chapter 3 Computer System

Class 9 Chapter 3 Computer System💻

Very Short Answer (Technical Term)

a. What is the unit which is used to enter data to the computer?
Ans: Input Unit
b. What is the unit that displays the result of processing?
Ans: Output Unit
c. What is the group of interrelated components that make up a body to perform a specific task in computer?
Ans: Computer System
d. What are the physical parts of computer system called?
Ans: Hardware
e. What is the device which is used to process data?
Ans: Central Processing Unit (CPU)
f. Who are the persons that operate the computer?
Ans: Users

Short Answer Questions

a. What is computer system?

Ans: The computer along with various hardware units and software that makes the computer function and performs the different tasks is collectively known a computer system.

b. List the main units of computer system.

Ans: The main units of computer system are:

• Computer hardware
• Computer software
• Data
• User

c. Draw a block diagram (Internal architecture) of computer system.

d. define data and user with example.

Ans: Data are the consists of individual facts or piece of information that by themselves may not make much sense to the people.

User are the people who operate the computer.

e. What is CPU? list its main sections.

Ans: CPU (central Processing Unit) are the main processing unit of the computer also considered as an electronic brain of computer. 

 Main sections of CPU are:

• Control Unit (CU)
• Arithmetic Logic Unit (ALU) 
• Register

f. Write the function of CU and ALU

Ans: The Control Unit (CU) manages and controls the execution of instructions by directing the flow of data between the CPU and other components.

The Arithmetic Logic Unit (ALU) performs all arithmetic operations (like addition, subtraction) and logical operations (like comparison of values).

g. What is an input device? List any two examples.

Ans: The devices that are used to enter data and instructions or commands into the computer are called input devices.

Example: Keyboard, Mouse

h. What is output device? Write with examples.

Ans: The output devices are the hardware components used to get output from the computer. Example: Monitor, Printer, Speaker etc.

i. Differentiate between Input device and output device.

Ans: 

Input device	Output device
The devices that are used to enter data and instructions or commands into the computer are called input devices.	The output devices are the hardware components used to get output from the computer.
Example: Keyboard, Mouse	Example: Monitor, Printer, Speaker

3. Long question:

a.Briefly describe computer Architecture with the help of diagrams.

Ans:

Diagrams of computer Architecture:

Computer architecture is the basic design and structure of a computer. It shows how different parts of the computer work together to process data.

There are three main parts:

1. Input Unit – Takes data and instructions from the user (e.g., keyboard, mouse).

2. Central Processing Unit (CPU) – The brain of the computer. It has:

• Control Unit (CU) – Controls the flow of data.

• Arithmetic Logic Unit (ALU) – Does calculations and comparisons.

• Register: Register is a small amount of storage available as part of CPU

3. Memory Unit – Stores data and instructions temporarily (RAM).

4. Output Unit – Shows the result (e.g., monitor, printer).

b. Explain memory and storage of computer systems in detail.

Ans:

Memory

Memory is the part of a computer that stores data and instructions temporarily while the computer is working. It is fast and helps the computer process tasks quickly.

Types of Memory:

1. RAM (Random Access Memory):
   
   

• It stores data temporarily.
  
  

• Data is lost when the power is turned off.
  
  

• It helps the CPU run programs.
  
  

2. ROM (Read-Only Memory):
   
   

• It stores important instructions permanently.
  
  

• Data is not lost when the computer is turned off.
  
  

• It is used to start the computer (booting).

Storage

Storage is used to store data, files, and programs permanently. Even when the computer is turned off, the data stays safe in storage.

Common Storage Devices:

1. Hard Disk Drive (HDD) – Used in most computers to store large files.
   
   

2. Solid State Drive (SSD) – Faster than HDD, with no moving parts.
   
   

3. Pen Drive/USB Drive – Portable storage device.
   
   

4. Memory Card – Used in mobile phones and cameras.

5. CD/DVD – Optical storage, used less today.