CBSE Class 11 Computer Science Syllabus 2025-26: The Ultimate Guide

Welcome to the exciting world of Computer Science! If you've chosen this subject, get ready for a journey that will challenge your logical thinking and empower you to become a creator of technology. The CBSE Class 11 Computer Science (CS) syllabus (Subject Code: 083) for the 2025-26 session is designed to build a rock-solid foundation in computational thinking, Python programming, and the ethical considerations of our digital world.

This detailed guide will walk you through the entire syllabus, helping you understand what to expect and how to prepare for success.

Learning Objectives: What Skills Will You Gain?

By the end of this course, you'll be able to:

• Develop basic computational thinking and understand algorithms.
• Master fundamental Python programming, including various data types.
• Understand the basics of computer architecture and operating systems.
• Explain the concepts of cyber ethics, safety, and crime.
• Appreciate the role of technology in society, considering gender and disability issues.

Theory Syllabus & Marks Distribution (Total: 70 Marks)

The theory portion is divided into three units, with a very strong emphasis on programming.

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A Deep Dive into Each Unit

Unit 1: Computer Systems and Organisation (10 Marks)

This unit lays the groundwork for understanding what a computer is and how it works.

• Computer Organisation: Get introduced to the basic components of a computer system: hardware, software, CPU, I/O devices, and memory (primary, cache, secondary).
• Software: Learn the difference between system software (like OS, device drivers) and application software.
• Boolean Logic & Number Systems: A key part of CS, this section covers logic gates (AND, OR, NOT, etc.), De Morgan's laws, and number systems (Binary, Octal, Decimal, Hexadecimal).
• Encoding Schemes: Understand how characters are represented using ASCII, ISCII, and Unicode.

Unit 2: Computational Thinking and Programming - 1 (45 Marks)

This is the heart of the Class 11 CS syllabus and carries the most weight. Your entire focus should be on mastering this unit.

• Problem-Solving & Python Basics: You will learn the steps to solve a problem (from algorithm to debugging) and get started with Python programming, covering everything from tokens and variables to execution modes.
• Data Types & Operators: Dive deep into Python's data types (Number, String, List, Tuple, Dictionary) and learn to use various operators (arithmetic, relational, logical, etc.).
• Control Flow: Master the use of conditional statements (if, if-else, if-elif-else) and iterative loops (for, while) to control your program's logic.
• Data Structures:
  • Strings: Learn to manipulate text using a vast library of built-in string methods.
  • Lists: Understand and use lists, a versatile data structure, with functions like append(), pop(), sort(), and more.
  • Tuples: Work with immutable sequences and their associated methods.
  • Dictionaries: Learn the power of key-value pairs for efficient data storage and retrieval.
• Python Modules: Get introduced to importing and using powerful modules like math, random, and statistics.

Unit 3: Society, Law, and Ethics (15 Marks)

This unit explores the responsible use of technology in the modern world.

• Digital Citizenship: Learn about digital footprints, net-etiquette, and data protection laws.
• Intellectual Property & Cyber Crime: Understand concepts like copyright, plagiarism, hacking, phishing, and cyber bullying.
• Cyber Safety: Learn how to browse the web safely and protect your identity.
• E-Waste & IT Act: Become aware of e-waste management and the key provisions of the Information Technology Act.

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Practical Examination Breakdown (Total: 30 Marks)

Your practical skills are just as important as theory. The practical exam is structured as follows:

• Lab Test (12 Marks): Your ability to write a logical, well-documented, and efficient Python program will be tested.
• Report File (7 Marks): You need to maintain a file with a minimum of 20 Python programs.
• Viva (3 Marks): Be prepared to answer questions based on your programs and project.
• Project (8 Marks): You will develop a small project using the Python concepts you've learned throughout the year.

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COMPUTER SCIENCE COMPLETE SYLLABUS

Subject Code - 083 Class XI (2025-26)

1. Learning Outcomes

Students should be able to: a) develop basic computational thinking b) explain and use data types c) appreciate the notion of algorithms d) develop a basic understanding of computer systems- architecture and operating system e) explain cyber ethics, cyber safety, and cybercrime f) understand the value of technology in societies along with consideration of gender and disability issues.

2. Distribution of Marks

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3. Unit wise Syllabus

Unit 1: Computer Systems and Organisation

• Basic computer organisation: Introduction to Computer System, hardware, software, input device, output device, CPU, memory (primary, cache and secondary), units of memory (bit, byte, KB, MB, GB, TB, PB)
• Types of software: System software (Operating systems, system utilities, device drivers), programming tools and language translators (assembler, compiler, and interpreter), application software
• Operating System(OS): functions of the operating system, OS user interface
• Boolean logic: NOT, AND, OR, NAND, NOR, XOR, truth tables and De Morgan's laws, Logic circuits
• Number System: Binary, Octal, Decimal and Hexadecimal number system; conversion between number systems
• Encoding Schemes: ASCII, ISCII, and Unicode (UTF8, UTF32)

Unit 2: Computational Thinking and Programming - I

• Introduction to Problem-solving: Steps for Problem-solving (Analyzing the problem, developing an algorithm, coding, testing, and debugging), representation of algorithms using flowchart and pseudocode, decomposition
• Familiarization with the basics of Python programming: Introduction to Python, Features of Python, executing a simple “hello world" program, execution modes: interactive mode and script mode, Python character set, Python tokens( keyword, identifier, literal, operator, punctuator), variables, concept of l-value and r-value, use of comments
• Knowledge of data types: Number(integer, floating point,complex), boolean, sequence(string, list, tuple), None, Mapping(dictionary), mutable and immutable data types.
• Operators: arithmetic operators, relational operators, logical operators, assignment operators, augmented assignment operators, identity operators (is, is not), membership operators (in not in)
• Expressions, statement, type conversion, and input/output: precedence of operators, expression, evaluation of an expression, type-conversion (explicit and implicit conversion), accepting data as input from the console and displaying output.
• Errors: syntax errors, logical errors, and run-time errors
• Flow of Control: introduction, use of indentation, sequential flow, conditional and iterative flow
• Conditional statements: if, if-else, if-elif-else, flowcharts, simple programs: e.g.: absolute value, sort 3 numbers and divisibility of a number.
• Iterative Statement: for loop, range(), while loop, flowcharts, break and continue statements, nested loops, suggested programs: generating pattern, summation of series, finding the factorial of a positive number, etc.
• Strings: introduction, string operations (concatenation, repetition, membership and slicing), traversing a string using loops, built-in functions/methods-len(), capitalize(), title(), lower(), upper(), count(), find(), index(), endswith(), startswith(), isalnum(), isalpha(), isdigit(), islower(), isupper(), isspace(),lstrip(), rstrip(), strip(), replace(), join(), partition(), split()
• Lists: introduction, indexing, list operations (concatenation, repetition, membership and slicing), traversing a list using loops, built-in functions/methods–len(), list(), append(), extend(), insert(), count(), index(), remove(), pop(), reverse(), sort(), sorted(), min(), max(), sum(); nested lists, suggested programs: finding the maximum, minimum, mean of numeric values stored in a list; linear search on list of numbers and counting the frequency of elements in a list.
• Tuples: introduction, indexing, tuple operations (concatenation, repetition, membership and slicing); built-in functions/methods — len(), tuple(), count(), index(), sorted(), min(), max(), sum(); tuple assignment, nested tuple; suggested programs: finding the minimum, maximum, mean of values stored in a tuple; linear search on a tuple of numbers, counting the frequency of elements in a tuple.
• Dictionary: introduction, accessing items in a dictionary using keys, mutability of a dictionary (adding a new term, modifying an existing item), traversing a dictionary, built-in functions/methods — len(), dict(), keys(), values(), items(), get(), update(), del, clear(), fromkeys(), copy(), pop(), popitem(), setdefault(), max(), min(), sorted(); Suggested programs: count the number of times a character appears in a given string using a dictionary, create a dictionary with names of employees, their salary and access them.
• Introduction to Python modules: Importing module using ‘import ' and using from statement, importing math module (pi, e, sqrt(), ceil(), floor(), pow(), fabs(), sin(), cos(), tan()); random module (random(), randint(), randrange()), statistics module (mean(), median(), mode()).

Unit 3: Society, Law and Ethics

• Digital Footprints
• Digital Society and Netizen: net etiquettes, communication etiquettes, social media etiquettes
• Data Protection: Intellectual property rights (copyright, patent, trademark), violation of IPR (plagiarism, copyright infringement, trademark infringement), open source software and licensing (Creative Commons, GPL and Apache)
• Cyber Crime: definition, hacking, eavesdropping, phishing and fraud emails, ransomware, cyber trolls, cyber bullying
• Cyber safety: safely browsing the web, identity protection, confidentiality
• Malware: viruses, trojans, adware
• E-waste management: proper disposal of used electronic gadgets.
• Information Technology Act (IT Act)
• Technology and society: Gender and disability issues while teaching and using computers

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4. Practical

5. Suggested Practical List

Python Programming

• Input a welcome message and display it.
• Input two numbers and display the larger / smaller number.
• Input three numbers and display the largest / smallest number.
• Generate the following patterns using nested loops:
  • Pattern-1: *, **, ***, ****, *****
  • Pattern-2: 12345, 1234, 123, 12, 1
  • Pattern-3: A, AB, ABC, ABCD, ABCDE
• Write a program to input the value of x and n and print the sum of the following series:
  • 1 + x + x² + x³ + x⁴ + ... xⁿ
  • 1 - x + x² - x³ + x⁴ - ... xⁿ
  • x + x²/2 + x³/3 + x⁴/4 + ... xⁿ/n
  • x + x²/2! + x³/3! + x⁴/4! + ... xⁿ/n!
• Determine whether a number is a perfect number, an Armstrong number or a palindrome.
• Input a number and check if the number is a prime or composite number.
• Display the terms of a Fibonacci series.
• Compute the greatest common divisor and least common multiple of two integers.
• Count and display the number of vowels, consonants, uppercase, lowercase characters in string.
• Input a string and determine whether it is a palindrome or not; convert the case of characters in a string.
• Find the largest/smallest number in a list/tuple
• Input a list of numbers and swap elements at the even location with the elements at the odd location.
• Input a list/tuple of elements, search for a given element in the list/tuple.
• Create a dictionary with the roll number, name and marks of n students in a class and display the names of students who have marks above 75.

6. Suggested Reading Material

• NCERT Textbook for Computer Science (Class XI) Complete Book
• Support Material on CBSE website Supported Material

The Class 11 Computer Science syllabus is intensive but incredibly rewarding. By focusing on building strong logical foundations and practicing programming consistently, you will be well-prepared for the challenges of Class 12 and beyond. Happy coding