CBSE Class 9 Foundation of Information Technology: Computer System Organisation NCERT Solutions

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NCERT Solutions PDF Class 9 PDF

This section provides detailed NCERT Solutions for Class 9 Foundation of Information Technology, Chapter 2, focusing on Computer System Organisation. It covers essential concepts like input devices, distinguishing between primary and secondary memory, understanding cache memory benefits, and defining storage units. The solutions explain the functionality of devices like webcams and memory cards, and clarify the differences between various memory types and storage capacities. These solutions are designed to help students grasp the fundamental principles of computer hardware and memory organisation, aiding in their exam preparation and revision.

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Quick info

BoardCBSE
ClassClass 9
SubjectFoundation of Information Technology
Session2026
LanguageEnglish
TypeNCERT Solutions
ChapterChapter 2

Chapter summary

Chapter 2 of the Foundation of Information Technology syllabus for Class 9 delves into Computer System Organisation. The NCERT Solutions cover key topics such as common input devices, the advantages and disadvantages of specific input technologies, the purpose of webcams, and the characteristics of primary and secondary memory. It also explains cache memory, optical discs, and differentiates between bits and bytes, providing a clear understanding of computer hardware components and data storage.

Learning outcomes

  • Identify and describe common input devices for computers.
  • Differentiate between primary and secondary memory based on their characteristics.
  • Explain the function and benefits of cache memory.
  • Understand the concept of a byte and its relation to a bit.
  • Recognize different types of optical discs created using laser technology.
  • Explain the purpose and usage of webcams and memory cards.

Topics covered

Paper topics

  • Input Devices
  • Keyboard
  • Webcam
  • Memory Types
  • Primary Memory (RAM)
  • Secondary Memory
  • Cache Memory
  • Optical Discs (ROM)
  • Storage Units
  • Bit
  • Byte
  • Memory Card

Important topics

  • Comparison of Primary and Secondary Memory
  • Role and Benefits of Cache Memory
  • Understanding Bits and Bytes
  • Function of Input Devices
  • Characteristics of RAM

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Questions and Solutions

Question 1.

Name the most commonly used input device.
Solution: The most commonly used input device is the keyboard. It is essential for entering text, numbers, commands, and directing the computer to perform specific actions.

Question 2.

Explain the main advantage and disadvantage of an Optical Character Reader ().
Solution: The main advantage of an Optical Character Reader () is its ability to accurately scan and recognize characters printed on paper using special fonts and conventional ink. However, a significant disadvantage is that it can only recognize a limited set of characters, which restricts its use to specific font types and sizes.

Question 3.

Why do we use a webcam?
Solution: A webcam is used primarily for capturing a sequence of digital images or video in real-time. These captured images or video streams are then transferred to a computer, where they can be processed, stored, or displayed, often for communication or surveillance purposes.

Question 4.

Name the memory (Primary/Secondary) with the following features:
  • If current is interrupted, data is lost.
  • Before a program is ready to run, the program is loaded into this memory, which allows the CPU directly access the program.
Solution: The memory described is Primary Memory, specifically Random Access Memory (RAM). RAM is volatile, meaning its contents are lost when the power is interrupted. It serves as the workspace for the CPU, holding programs and data that are actively being used or are ready to be executed.

Question 5.

Write any one advantage of cache memory.
Solution: An advantage of cache memory is that it significantly speeds up data access. If the data the CPU needs is found in the cache (a cache hit), the CPU can retrieve it much faster than accessing it from the main system memory (RAM) via the motherboard's system bus, leading to quicker processing.

Question 6.

Which disc is created using laser beam?
Solution: A ROM disc (Read-Only Memory disc), such as a CD-ROM or DVD-ROM, is created using a laser beam during the manufacturing process to permanently etch data onto the disc surface.

Question 7.

Give one difference between primary and secondary memory.
Solution: One key difference is volatility and capacity. Primary memory (like RAM) is volatile, meaning it loses data when power is off, and typically has a smaller storage capacity. Secondary memory (like hard drives or SSDs) is non-volatile, retaining data without power, and offers much larger storage capacities.

Question 8.

Arrange the following memory units in ascending order of their storage capacities: Kilobyte, Byte, Terabyte, Megabyte, Geopbyte
Solution: The memory units arranged in ascending order of their storage capacities are: Byte, Kilobyte, Megabyte, Terabyte, Geopbyte. This order reflects increasing data storage capability.

Question 9.

Where can a memory card be used?
Solution: A memory card is a versatile storage device that can be used in a wide range of electronic devices. Common examples include digital cameras, smartphones, camcorders, portable audio players, video players, Personal Digital Assistants (PDAs), gaming consoles, laptops, and printers.

Question 10.

Define the term byte. Differentiate between a bit and a byte.
Solution: A byte is a fundamental unit for measuring digital data storage. It is typically composed of 8 bits. A bit (binary digit) is the smallest unit of data in computing and can have only one of two values: 0 or 1. Therefore, a byte represents a larger chunk of information than a single bit.

Question 1.

Differentiate between and OMR.
Solution:
  • stands for . It is used to read characters from special type fonts printed on conventional paper using conventional ink. technology can interpret letters and numbers into machine-readable code.
  • OMR stands for Optical Mark Recognition. It is used to detect the presence or absence of a mark in a specific position on a form, such as in multiple-choice answer sheets. It reads marks made by a pencil or pen in predefined areas.
The key difference lies in what they recognize: recognizes characters, while OMR recognizes the presence or absence of marks in specific locations.

Common mistakes

  • Confusing volatile and non-volatile memory.
  • Incorrectly ordering memory units by storage capacity.
  • Misunderstanding the difference between a bit and a byte.
  • Not clearly differentiating between primary and secondary memory characteristics.

Revision tips

  • Review the definitions and examples of all input devices mentioned.
  • Create a table to compare the features of primary and secondary memory.
  • Practice converting between different memory units (bit, byte, KB, MB, etc.).
  • Understand the role of cache memory in speeding up computer operations.

Practice MCQs

Q1. Which of the following is the most commonly used input device for typing commands and data?

Q2. What is the main characteristic of primary memory (like RAM) when the power is interrupted?

Q3. Which type of memory allows the CPU direct access to a program before it is ready to run?

Q4. A ROM disc is created using which technology?

Q5. How many bits typically form one byte?

Frequently asked questions

What are the main input devices discussed in Chapter 2?

Chapter 2 discusses the keyboard as the most commonly used input device and also mentions webcams for capturing digital images.

What is the key difference between primary and secondary memory?

Primary memory (like RAM) is volatile and has limited storage, while secondary memory is non-volatile and can store large amounts of data.

Why is cache memory important?

Cache memory is important because it speeds up data processing by storing frequently accessed data closer to the CPU, reducing the need to access slower main memory.

How are bits and bytes related?

A bit is the smallest unit of data (0 or 1), and a byte is a group of 8 bits, commonly used for measuring storage capacity.

What is the purpose of a webcam?

A webcam is used to capture a series of digital images or video, which can then be transferred and displayed by a computer.

Which memory unit is larger: a Megabyte or a Kilobyte?

A Megabyte (MB) is larger than a Kilobyte (KB). The order of increasing capacity is Byte, Kilobyte, Megabyte, Terabyte, Geopbyte.

Important links

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