CBSE Class 11 Computer Science Syllabus 2026-27

COMPUTER SCIENCE Subject Code - 083 Class XI (2026-27)

1. Learning Outcomes

Students should be able to:

1. develop basic computational thinking
2. explain and use data types
3. appreciate the notion of algorithms
4. develop a basic understanding of computer systems- architecture and operating system
5. explain cyber ethics, cyber safety, and cybercrime
6. understand the value of technology in societies along with consideration of gender and disability issues.

2. Distribution of Marks

Jnit No. Unit Name Marks

1 Computer Systems and Organisation 10

2 Computational Thinking and Programming -1 45

3 Society, Law, and Ethics 15 70

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)

<math>\blacktriangle</math> 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

lacktrian 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

<math>\blacktriangle</math> 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 I-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.

<math>\blacktriangle</math> 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()

lacktrian 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.

lacktrian 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.

<math>\blacktriangle</math> Introduction to Python modules: Importing module using 'import <module>' 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

<math>\blacktriangle</math> 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

1. 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

4. Practical

S.No. Unit Name Marks (Total=30)

1. Lab Test (12 marks)

Python program (60% logic + 20% documentation + 12

20% code quality)

1. Report File + Viva (10 marks)

Report file: Minimum 20 Python programs 7

Viva voce 3

1. Project (that uses most of the concepts that have been 8 learnt)

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 Pattern-3

****

• 12345 Α
• 1234 AB
• 123 ABC
• 12 ABCD

Write a program to input the value of x and n and print the sum of the following series:

<math>\rightarrow</math> 1 + x + x² + x³ + x⁴ + ... xⁿ <math>\rightarrow</math> 1 - <math>x</math> + <math>x^2</math> - <math>x^3</math> + <math>x^4</math> - <math>x^n</math> <math>x + \frac{x^2}{2} + \frac{x^3}{3} + \frac{x^4}{4} + \cdots + \frac{x^n}{n}</math> <math>x + \underline{x^2} + \underline{x^3} + \underline{x^4} + \cdots \underline{x^n}</math>

• 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

lacktrian NCERT Textbook for Computer Science (Class XI)

Support Material on CBSE website