CBSE Class 12 · Computer Science

CBSE Class 12 Computer Science Board Exam Preparation

Python, data structures, networks, and SQL — the most scoring board subject for tech students

Complete chapter-wise preparation guide for CBSE Class 12 Computer Science board exam 2025-26. Covers Python file handling, stacks, computer networks, and database management with SQL and Python-MySQL connectivity — marks distribution, important programs, and strategy.

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Theory Marks

Practical Marks

3 hours

Exam Duration

Total Chapters

Chapter-Wise Marks Breakdown

70 theory marks

Chapter	Marks	Difficulty	Key Topics
Python Revision Tour	5	Easy	Data Types · Mutable vs Immutable · List/Tuple/Dict
Exception Handling	6	Medium	try-except-finally · Multiple except Clauses · raise Statement
File Handling	12	Medium	Text Files (read/write/append) · Binary Files with pickle — dump() & load() · CSV Files with csv module
Data Structures: Stack	10	Hard	Stack using Python List · PUSH & POP Operations · Overflow & Underflow Conditions
Computer Networks	15	Medium	OSI & TCP/IP Model · Network Topologies (Bus, Star, Tree) · Network Devices (Hub, Switch, Router, Gateway)
Database Concepts & SQL	12	Medium	RDBMS concepts & Keys (Primary, Candidate, Foreign) · SQL DDL (CREATE, ALTER, DROP) · SQL DML (SELECT, INSERT, UPDATE, DELETE)
MySQL-Python Connectivity	10	Easy	mysql-connector-python · connect() and cursor() · execute(), commit()

Topics That Appear Every Year

01File handling programs — read all lines, count words, copy file, search specific line in text file

02Binary file using pickle — writing and reading a list of dictionaries

03Stack PUSH/POP implementation using Python list — full program with display function

04SQL: SELECT with WHERE, GROUP BY, HAVING, ORDER BY — 3+ complex queries

05SQL JOINS — write queries using EQUI JOIN and NATURAL JOIN with 2 tables

06Network topologies — Bus, Star, Tree diagrams with advantages/disadvantages

07Python-MySQL: complete program to insert and fetch records with conditions using cursor

Study Strategy for 90+

Unit 1 (Computational Thinking and Programming — Python, Exception, File Handling, Stack) carries the most marks — practice all programs by hand

File handling is the highest-weight topic — master all 3 types (text, binary, CSV) — exam asks 1 program of each type

Stack: implement PUSH, POP, PEEK, DISPLAY as separate functions — 10 marks, always asked

Networks (15 marks) is 100% theory — one-page summary of all protocols, devices, port numbers

SQL carries 12 marks and is fully predictable — master SELECT queries with all 6 clauses

Practical carries 30 marks — write clean programs and practise all mysql-connector methods

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