CBSE Class 12 Computer Science (083) – 2025–2026

Detailed Chapter-wise Analysis • Important Topics • Keywords • Repeated Questions

Unit 1 – Python Revision & Functions

Marks: 8–12 • Very important unit – foundation for all programming questions

• Key Topics: Functions (parameters, return, scope), recursion, modules (import, from), exception handling (try-except-finally), lambda, list comprehension
• Important Keywords: def, return, global, nonlocal, recursive, try, except, finally, raise, lambda, list comprehension, map, filter
• Most Repeated Questions:
  • Write a recursive function to calculate factorial / Fibonacci
  • Explain scope of variables with global/local example
  • Handle ZeroDivisionError / FileNotFoundError in code
  • Use lambda with map/filter on list

Unit 2 – File Handling

Marks: 6–10 • High-weightage practical + theory

• Key Topics: Text file (read, write, append), binary file (pickle), CSV file handling, seek(), tell()
• Important Keywords: open(), close(), read(), readline(), readlines(), write(), writelines(), seek(), tell(), pickle.dump/load, csv.reader/writer
• Most Repeated Questions:
  • Read a text file and count words / lines / vowels
  • Write a program to copy content from one file to another
  • Use pickle to store/retrieve list of records
  • Read CSV file and display records in tabular format

Unit 3 – Using Python Libraries

Marks: 4–8 • Moderate weightage

• Key Topics: math, random, statistics modules, pandas basics (Series, DataFrame)
• Important Keywords: import math, math.sqrt/ceil/floor/pow, random.randint/randrange/choice/shuffle, statistics.mean/median/mode
• Most Repeated Questions:
  • Generate 10 random numbers between 1–100
  • Find square root, factorial using math module
  • Calculate mean, median of a list using statistics

Unit 4 – Data Structures (Stack & Queue)

Marks: 8–12 • Very high weightage – theory + code

• Key Topics: Stack (LIFO), Queue (FIFO), implementation using list/class, applications
• Important Keywords: push, pop, peek, is_empty, enqueue, dequeue, front, rear, overflow, underflow
• Most Repeated Questions:
  • Implement stack using list with push/pop/peek
  • Implement queue using list with enqueue/dequeue
  • Explain applications of stack (expression evaluation) & queue (printer queue)

Unit 5 – Computer Networks

Marks: 6–10 • Theory heavy

• Key Topics: Network types, topologies, devices, protocols, IP addressing, OSI/TCP-IP model
• Important Keywords: LAN, WAN, MAN, star, bus, ring, hub, switch, router, TCP/IP, HTTP, FTP, IPv4/IPv6
• Most Repeated Questions:
  • Differentiate LAN vs WAN
  • Explain star topology advantages/disadvantages
  • What is TCP/IP model? Layers & functions

Exam Strategy – Computer Science (2026 Boards)

1. Most repeated units: SQL (10–15 marks), Python-SQL (8–12 marks), Stack/Queue (8–12 marks)
2. SQL questions: Write exact syntax, proper indentation, table/column names
3. Python code: Meaningful variables, 2–3 comments, exception handling if asked
4. Time management: 15–18 min for 10–12 mark questions
5. Practice: Last 5 years papers + CBSE sample paper 2025–26

This guide covers complete Class 12 CS syllabus as per 2025–2026 CBSE guidelines.