In this chapter, Components of Computer System: CBSE Class 9 Notes with Diagram, we will explore the major building blocks that make up a computer, such as the Central Processing Unit (CPU), memory, storage devices, and input/output (I/O) devices. These elements work together like parts of a team, each with a specific role, to make the computer system function efficiently. Whether it is typing an assignment, browsing the internet, creating a presentation, or watching a video, all of these tasks are possible because of the perfect coordination between the various components of the computer system.
In today’s world, the computer has become one of the most important tools in our daily life, whether it is for education, business, entertainment, or communication. But to truly understand how this wonderful machine works, it is important to know what is computer system and how its different parts work together.
A computer system is not just a single device, it is a combination of hardware, software, and processes that enable us to input data, process it, store it, and get useful information as output. The computer operating system plays a vital role here, acting like a manager which controls and coordinates all the activities of the computer’s components.
When we look deeper into the Components of Computer System, it becomes clear that every part plays a unique role in processing and managing information. The CPU, often called the “brain of the computer,” processes instructions and carries out tasks. Memory (RAM) temporarily stores data and instructions for quick access, while storage devices like hard drives and SSDs keep information safe for long-term use.
Input devices, such as a keyboard and mouse, help us give commands, and output devices, such as monitors and printers, present the processed information back to us. In modern times, the convergence of technologies has brought together computers, smartphones, televisions, and other gadgets into interconnected systems, making digital life faster and more efficient. For students, understanding the computer system drawing of these components is very helpful, as it gives a visual idea of how the parts are connected and how information flows inside the machine.
Components of Computer System: CBSE Class 9 Notes with Diagram, this introduction will not only help you identify the physical parts of a computer system but also explain their functions, applications, and importance in everyday life. By the end of this chapter, you will have a strong understand computers better, which will be useful not only for exams but also for practical use in the digital age.
Table of Contents
Components of Computer System: CBSE Class 9 Notes with Diagram Solved
Q1. What is the full form of COMPUTER?
Answer: Commonly Operated Machine Particularly Used for Technological and Educational Research.
Q2. What is a computer?
Answer: A computer is an automatic, electronic calculating device that can process a given input in a prescribed manner to produce a desired output at a very high speed with remarkable accuracy.
Q3. Characteristics of a computer?
Answer: If we discuss some characteristics of a computer, then only we can understand what is a computer? Why do we use computers? And what can a computer do?
Some important characteristics of a computer:
- Speed: The computer works very fast. A computer can calculate millions of calculations in a second, which we humans will take hours to complete.
- Accuracy: A computer provides accurate output. The output of a computer depends on the instructions of the input data.
- Versatility: A computer can perform various tasks like office work, playing music, games etc.
- Storage: A computer can store huge amounts of data. Once stored, we can retrieve the data instantly. Because computer has an in-built memory. We also can use secondary memory in a computer, like pen drive, external hard drive, etc.
- Automatic Operations: If we give an instruction like five operations one by one then the computer can perform automatic operations according to the instruction without any manual intervention.
Q4. What are the limitations of computers?
Answer: Computer is a smart machine, but there are some limitations of computers:
- Zero-IQ: Computers has lack decision-making ability. Computers can not think and take decisions by themselves. We users need tell everything to a computer. Otherwise, a computer is a zero-IQ dumb machine.
- No Experience: A computer does not learn anything from its past experience.
- Feelingless: A computer does not have feelings, emotions, taste, knowledge, or experience.
Q5. What are the components of computer system?
Answer: A computer consists mainly of four units: input unit, memory unit, processing unit, and output unit. It works through an interaction of hardware and software.
- Input Unit: The input unit is like the “mouth” of the computer. It takes information or instructions from us (through devices like a keyboard, mouse, or scanner) and sends them to the computer for processing.
- Memory Unit: The memory unit is like the “brain” of the computer system. It stores data and instructions temporarily (RAM) or permanently (hard drive, SSD) so the computer can use them when needed.
- Processing Unit: This unit is like the “thinking part” of the computer, also called the CPU. It follows instructions, does calculations, and makes decisions to produce results.
- Output Unit: This unit is like the “voice” or “display” of the computer. Output unit shows us the results of the computer’s work through devices like a monitor, printer, or speakers.
Q6. What is hardware?
Answer: The physical components or devices attached to the computers are called hardware.
Q7. What is software?
Answer: Software is a set of computer programs that is used to do the work of a computer.
Q8. What is IPO process?
Answer: It refers to input-process-output-process. All processes in computer go through the IPO process. It actually shows how a computer works.
Q9. What is the use of a processing unit?
Answer: This unit does all the processing work in the computer, like the CPU (central processing unit). It is also called the brain of a computer.
Q10. What is the use of a memory unit?
Answer: This unit is specially used for storing the data and instructions.
Q11. What are the main parts of CPU?
Answer: ALU (arithmetic logic unit), CU (control unit), and registers.
Q12. Explain DDR RAM?
Answer: It is based ob SDRAM architecture, but it utilizes the clock signal differently to transfer twice the data in the same amount of time.
Q13. What is cache?
Answer: It is a type of RAM. Cache is fast memory that is built into the computer’s CPU or located next to it on a separate chip.
Work Out Time (Components of Computer System)
A. Choose the correct answer. (Components of Computer System)
1. Which of the following is not the characteristic of computer?
- (a) speed
- (b) feelings
- (c) Obedience
- (d) Storage
Answer: Feelings.
2. Which of the following are the basic application areas of computer?
- (a) Business
- (b) Research
- (c) Education
- (d) all of these
Answer: All of these.
3. A computer basically made up of parts.
- (a) Two
- (b) Three
- (c) Four
- (d) Five
Answer: Two
4. Which unit is responsible to give data/instructions to computer?
- (a) Output Unit
- (b) Processing Unit
- (c) Input Unit
- (d) None of these
Answer: Input Unit
5. Which type of memory is primarily used by computer for booting of system?
- (a) Primary memory
- (b) Secondary memory
- (c) Both of these
- (d) None of these
Answer: Primary memory
6. Which of the following is a part of CPU?
- (a) ALU
- (b) CU
- (c) Registers
- (d) All of these
Answer: All of these
7. _______________ coordinates the components of computer system?
- (a) ALU
- (b) CU
- (c) Registers
- (d) Cache
Answer: CU
B. Short answer type questions. (Components of computer system)
1. Write the limitations of computer?
Answer: Limitations of computer are
- Zero IQ: Cannot think or decide on its own.
- No Feeling: Cannot feel emotions or understand human feelings.
- Can not learn from any past Experience.
2. Write about basic components of computer?
Answer: Basic components of computer system are,
- Input unit
- Memory unit
- Processing unit (CPU)
- Output unit
3. What are three parts of CPU?
Answer: Three parts of CPU( central processing unit) are,
- ALU – for calculation and logical works.
- CU – control the working of the computer.
- Registers – store small amount of data quickly.
4. What is main memory? Give an example.
Answer: Main memory is the primary storage the CPU uses to store data temporarily. Example: RAM.
5. What is the use of ROM?
Answer: ROM stores the instructions needed for starting (booting) the computer.
6. Write the differences between RAM vs ROM?
Answer: Differences between RAM and ROM,
| RAM | ROM |
|---|---|
| Temporary Memory | Permanent Memory |
| Data is lost when power is off (volatile memory) | Data is not lost (non volatile memory) |
| Use for running programs | Use for booting the system. |
7. Write the uses of computer in the education field.
Answer: There are lot of uses of computer in the education field like,
- Online Classes or E-learning.
- Digital notes and e-books.
- Educational videos and presentations.
8. Write the uses of computer in the science, research, and engineering field.
Answer: There are lot of uses of computer in the scince, research and engineering field like,
- Data analysis and research.
- Machines and buildings design.
- Running different types of experiments.
9. Write the uses of computer in the communication field.
Answer: There are lot of uses of computer in the communication field like,
- Email, chatting, and video calls.
- Social media.
- Online meetings.
10. Write the uses of computer in the banks.
Answer: There are lot of uses of computer in the banks like,
- for store customer records.
- online banking and ATM services.
- Money transfer process.
11. Write the uses of computer in the entertainment field.
Answer: There are lot of uses of computer in entertainment field like,
- Watching movies and listening to music.
- Playing games.
- Editing photos and videos.
12. Write the uses of computer by military. (Components of computer system)
Answer: There are lot of uses of computer by military like,
- Control weapons and defense systems.
- Train soldiers with simulations.
- Secure communication.
13. Write the uses of computer by police for law and enforcement.
Answer: There are lot of uses of computer by police for law and enforcement like,
- store criminal records.
- track and investigate crimes.
- use CCTV and surveillance systems
C. Long answer type questions. (Components of computer system)
1. Explain following types of RAM: DRAM, SRAM and DDR RAM.
Answer:
- DRAM(Dynamic RAM) – Stores each bit of data in a tiny capacitor. Needs to be refreshed many times per second. It is slower but cheaper.
- SRAM (Static RAM) – Stores data in flip-flops. No need for refreshing. It is faster but more expensive.
- DDR RAM (Double data rate RAM) – Transfers data twice in one clock cycle, making it faster than normal RAM. Used in modern computers for better performance.
2. Explain following types of ROM: PROM, EPROM and EEPROM.
Answer:
- PROM (Programmable ROM) – It can be programmed only once by the user. After that, data cannot be changed.
- EPROM (Erasable programmable ROM) – It can be erased by ultraviolet (UV) light and reprogrammed.
- EEPROM (Electrically Erasable Programmable ROM) – It can be erased and reprogrammed using electricity. Used in BIOS and other firmware.
3. What is cache? Also write its use. (Components of computer system)
Answer: Cache is a small, high-speed memory located inside or near the CPU.
Use – It stores frequently used data and instructions so that the CPU can access them quickly without going to the main memory (RAM). This makes the computer work faster.
D. Fill in the blanks. (Components of computer system)
1. A computer can perform all and functions.
Answer: A computer can perform all mathematical and logical functions.
2. Computer can perform millions of calculations per .
Answer: Computer can perform millions of calculations per second.
3. The components attached to the computer are called .
Answer: The external components attached to the computer are called peripherals.
4. is a set of program.
Answer: Software is a set of program.
5. A process in computer goes through cycle.
Answer: A process in computer goes through input–process–output cycle.
6. A CPU has three parts (i) , (ii) and (iii) .
Answer: A CPU has three parts (i) ALU, (ii) CU and (iii) Registers.
7. A computer is a dumb machine with IQ.
Answer: A computer is a dumb machine with zero IQ.
8. unit holds the data and instructions.
Answer: Memory unit holds the data and instructions.
9. Cache memory is a type of RAM i.e. .
Answer: Cache memory is a type of RAM i.e. static RAM (SRAM).
E. State true or false. (Components of computer system)
1. Computer has lack of decision making ability.
Answer: True ✅
2. Secondary memory is the main memory of the computer.
Answer: False ❌
3. Hard Disk is used to store data permanently.
Answer: True ✅
4. Processing unit provides the result of teh operation performed by computer.
Answer: False ❌
5. RAM and ROM are the examples of primary memory.
Answer: True ✅
6. A computer is basically made up of two parts: live ware and software.
Answer: False ❌
7. ALU controls all the hardware parts of the computer.
Answer: False ❌
F. Practical/lab activity. (Components of computer system)
1. Surff the internet and find the applications of computer( with the areas where computers are being used, with their images).
Answer: Applications of computers:
1.
Education – Online learning, digital classrooms, e-books.
2.
Business – Billing, inventory, accounting.
3.
Science & Research – Data analysis, space research.
4.
Communication – Email, video calls, messaging.
2. Divide the class in four groups. Name each group on a hardware unit e.g., Input Unit, Processing Unit, Output Unit, Memory Unit. Ask each group to carefully study the properties of their related hardware devices with their mode of use and make scrap book.
Answer: You can do it by yourself like playing games. Example Group Activity Plan:
- Group 1 – Input Unit: Study keyboard, mouse, scanner, microphone. Write uses and paste pictures.
- Group 2 – Processing Unit: Study CPU, ALU, CU, registers. Describe their roles.
- Group 3 – Output Unit: Study monitor, printer, speakers, projector. Show how they give results.
- Group 4 – Memory Unit: Study RAM, ROM, hard disk, pen drive. Write about storage types.
3. Draw the outline of IPO process on a chart(with its explanation). ((Components of computer system))
Answer: You can draw this image.
Explanation:
- Input – We give data to the computer.
- Processing – The CPU works on the data according to instructions.
- Output – The result is shown on output devices like monitor or printer.
Example: Addition of two numbers
- Input – Two numberrs arre given to the computer using input device.
- Processing – Addition operation performed on these two numbers.
- Output – Result is displayed on the screen.