CBSE Class 11 Informatics Practices — NCERT Solutions

Given: We need to identify the software that makes a computer functional and state its two primary services.

Answer:

The software required to make a computer functional is the Operating System (OS).

Examples: Windows, Linux, macOS, Ubuntu.

Two Primary Services of an Operating System:

1. Process Management: The operating system manages the execution of processes (programs in execution). It schedules processes, allocates CPU time, and ensures that multiple processes can run efficiently without conflict.

2. Memory Management: The operating system manages the primary (main) memory of the computer. It keeps track of each memory location — whether it is free or occupied — and allocates/deallocates memory to processes as needed, ensuring maximum utilisation of available memory.

Given: A program is written in a high-level language (e.g., Python, C++, Java).

Concept: A computer can only understand machine code (binary language — 0s and 1s). It cannot directly understand high-level language instructions.

Answer:

A program written in a high-level language (called source code) must be translated into machine code (binary code) before the computer can execute it. This translation is done by special system software called translators, which are of the following types:

1. Compiler: Translates the entire source code into machine code at once, producing an executable file. The compiled machine code can then be executed directly by the CPU.

2. Interpreter: Translates and executes the source code line by line, one statement at a time.

3. Assembler: Converts assembly language code into machine code.

Thus, the computer understands a high-level language program only after it has been converted into machine code by a compiler or interpreter.

Cloud-based services commonly used today include:

1. Google Drive / OneDrive / Dropbox – Cloud storage for files, photos and documents.
2. Gmail / Outlook – Web-based email services hosted on the cloud.
3. Google Docs / Microsoft 365 – Online word processing, spreadsheets and presentations.
4. YouTube / Netflix / Hotstar – Cloud-based video streaming platforms.
5. Google Classroom / DIKSHA – Cloud-based e-learning platforms.
6. WhatsApp / Telegram – Messaging apps that store media and chats on the cloud.
7. iCloud / Google Photos – Automatic cloud backup of photos and contacts.
8. Zoom / Google Meet – Cloud-based video conferencing services.

All these services allow users to access data and applications from any device connected to the internet, without needing local storage or processing power.

Internet of Things (IoT):

The Internet of Things (IoT) is a network of physical devices (things) embedded with sensors, software, and other technologies that enable them to connect and exchange data with other devices and systems over the internet — without requiring human-to-human or human-to-computer interaction.

Key idea: Everyday objects become 'smart' by being connected to the internet.

Potential Applications of IoT:

Thus, IoT connects the physical world to the digital world, enabling automation and real-time monitoring across virtually every sector.

Invalid identifier names are:

• a) Serial_no. — contains a dot (.), which is not allowed.
• b) 1st_Room — starts with a digit, and an identifier cannot start with a digit.
• c) Hundred$`** — contains **`$, a special symbol not allowed.
• d) Total Marks — contains a space, which is not allowed.
• f) total-Marks — contains a hyphen (-), which is not allowed.
• h) True — it is a keyword/reserved word, so it cannot be used as an identifier.

Valid identifiers are e) Total_Marks and g) _Percentage.

The required assignment statements are:

length = 10
breadth = 20

sum = (length + breadth) / 2

stationery = ['Paper', 'Gel Pen', 'Eraser']

first = 'Mohandas'
middle = 'Karamchand'
last = 'Gandhi'

fullname = first + ' ' + middle + ' ' + last

The blank spaces are added using ' ' so the full name is joined properly.

sort() changes the list in place and arranges the elements in ascending order.

So after sorting:

• original list: [12, 32, 65, 26, 80, 10]
• sorted list: [10, 12, 26, 32, 65, 80]

print(list1) displays that sorted list.

For each service, maintain the data fields needed to identify the person/item and perform the task:

a) Declare exam results and print e-certificates

• Student name
• Roll number / registration number
• Class
• Subject-wise marks
• Total marks / percentage
• Result status
• Certificate number

b) Register participants in an exhibition and issue biometric ID cards

• Participant name
• Age
• Gender
• Address / contact details
• Exhibition category / stall or item name
• Photograph
• Biometric data such as fingerprint / iris scan
• ID card number

c) To search for an image by a search engine

• Image file name
• Image format/type
• Keywords / tags
• Title / description
• Size / resolution
• Source / web page link

d) To book an OPD appointment with a hospital in a specific department

• Patient name
• Age / gender
• Contact number
• OPD registration number
• Department name
• Doctor name
• Appointment date and time
• Patient ID / medical record number

NumPy stands for Numerical Python. It is a Python package used for data analysis and scientific computing. It uses a multidimensional array object and provides tools for working with arrays. To install it, type:

pip install NumPy

A database is a collection of logically related records.

• ALTER → Change the name of a column
• UPDATE → Update existing information in a table
• DELETE → Delete an existing row from a table
• INSERT INTO → Insert the values in a table
• CONSTRAINTS → Restrictions on columns
• DESC → Table definition
• CREATE → Create a database