Computer System NCERT Solutions | Computer Science for Class 11 - Humanities/Arts PDF Download

Q1: Name the software required to make a computer functional. Write down its two primary services.
Ans: An Operating System (OS) is essential for a computer's operation. It manages memory by handling allocation and deallocation of primary memory when programs run and exit. Additionally, the OS manages devices connected to the computer by communicating with device drivers, which in turn communicate with the hardware.

Q2: How does the computer understand a program written in high level language?
Ans: Computers natively understand only machine language (binary code), so programs written in high-level languages need to be translated into machine language. This translation is done by compilers or interpreters, which convert high-level language code into machine code.

Q3: Why is the execution time of the machine code less than that of source code?
Ans: Machine code is a direct translation of source code (written in high-level or assembly languages) into the language that the computer's hardware can execute. Since machine code is directly executable without the need for further translation, its execution time is significantly shorter.

Q4: What is the need of RAM? How does it differ from ROM?
Ans: RAM (Random Access Memory) is volatile memory used to store data and programs temporarily while the computer is operating. In contrast, ROM (Read Only Memory) is non-volatile and permanently stores critical data needed for the computer's operations, like firmware.

Q5: What is the need for secondary memory?
Ans: Secondary memory is used for long-term data storage. It stores data and programs outside the computer's primary memory (RAM), allowing data to be retained even when the computer is turned off.

Q6: How do different components of the computer communicate with each other?
Ans: Components within a computer communicate via buses, which are pathways for data transfer. The data bus carries actual data, the address bus carries memory addresses so the system knows where to send or retrieve data, and the control bus carries control signals.

Q7: Draw the block diagram of a computer system. Briefly write about the functionality of each component.
Ans: The computer system includes:

• CPU: Central Processing Unit, divided into the Arithmetic Logic Unit (ALU) for performing operations and the Control Unit (CU) for directing operations.
• Input Devices: Such as keyboards and mice, allow users to enter data.
• Output Devices: Such as monitors and printers, output data from the computer.
• Storage Devices: Such as hard drives and SSDs, store data permanently.

Q8: What is the primary role of system bus? Why is data bus is bidirectional while address bus is unidirectional?
Ans: The system bus facilitates communication among the CPU, memory, and other peripherals. The data bus is bidirectional to allow both reading data from and writing data to memory. The address bus is unidirectional because it only sends memory addresses from the CPU to the memory.

Q9: Differentiate between proprietary software and freeware software. Name two software for each type.
Ans: 

Q10: Write the main difference between microcontroller Notes and microprocessor. Why do smart home appliances have a microcontroller instead of microprocessor embedded in them?
Ans: A microcontroller is a compact integrated circuit designed to govern a specific operation in an embedded system. It includes a CPU, memory, and peripherals on a single chip. Microprocessors are more general-purpose CPUs used in PCs. Microcontrollers are used in smart appliances for their efficiency and ability to handle specific tasks, like monitoring temperature or controlling lights with minimal power consumption.

Q11: Mention the different types of data that you deal with while browsing the Internet.
Ans: While browsing, you encounter:

• Structured Data: Clearly defined and easy to search, like database entries.
• Unstructured Data: No predefined format, like emails or videos.
• Semi-structured Data: Not organized in a traditional database but has some organizational properties, like HTML pages.

Q12: Categorise the following data as structured, semi structured and unstructured:

• Newspaper
• Cricket Match Score
• HTML Page
• Patient records in a hospital

Ans:

• Newspaper: Unstructured, as it contains various forms of data like text, images, and advertisements without a set format.
• Cricket Match Score: Semi-structured, because it has a regular format but isn't in a rigid database structure.
• HTML Page: Semi-structured, as it includes elements that are marked with tags although not in rigid database format.
• Patient Records: Structured, as they are stored in databases with consistent formats.

Q13: Name the input or output device used to do the following:
(a) To output audio
(b) To enter textual data
(c) To make hard copy of a text file
(d) To display the data or information
(e) To enter audio-based command
(f) To build 3D models
(g) To assist a visually-impaired individual in entering data
Ans: 
(a) Speaker outputs audio. 
(b) Keyboard is used for entering text. 
(c) Printer creates hard copies of documents. 
(d) Monitor displays data and information. 
(e) Microphone allows for audio input. 
(f) 3D Printer creates three-dimensional models. 
(g) Braille Keyboard enables visually-impaired individuals to input data.

Q14: Identify the category (system, application, programming tool) of the following software:
(a) Compiler
(b) Assembler
(c) Ubuntu
(d) Text editor
Ans: 
(a) Compiler: System software, translates code from high-level to low-level language. 
(b) Assembler: System software, converts assembly language to machine code. 
(c) Ubuntu: System software, an operating system based on Linux. 
(d) Text Editor: Programming tool, used for editing and writing code.