CBSE Deleted Syllabus 2026 — Class 10 & 12 Removed Topics
Full list of deleted/rationalised topics from the CBSE Class 10 & 12 syllabus 2026 — subject-wise removed chapters, what's still in the board exam, and the official source.
CBSE has rationalised the syllabus for 2025–2026, removing certain topics from Class 10 and 12. Deleted topics will NOT appear in board exams. Download the official rationalised syllabus from cbseacademic.nic.in. Below is the subject-wise list of key deleted topics so you can focus your preparation efficiently.
Where to Check the Official Deleted Syllabus
| Source | URL | What to Look For |
|---|---|---|
| CBSE Academic | cbseacademic.nic.in | Curriculum → Rationalised Syllabus 2025–26 |
| CBSE Main | cbse.gov.in | Academic → Curriculum |
Important: The rationalised syllabus document clearly marks which portions are "Deleted for Assessment" and which are "Retained." Only retained portions will appear in board exams.
Class 10 — Key Deleted Topics
Mathematics
| Chapter | Deleted/Reduced Topics |
|---|---|
| Real Numbers | Euclid's Division Lemma (proof), Fundamental Theorem of Arithmetic (proof — only statement is required) |
| Polynomials | Division algorithm for polynomials (statement only, no problems), relationship between zeros and coefficients of cubic polynomials |
| Pair of Linear Equations | Cross-multiplication method, problems reducible to linear equations in two variables |
| Triangles | Proof of BPT (Basic Proportionality Theorem) — only statement and application required |
| Constructions | Entire chapter reduced to only division of line segment and tangent to circle |
Science
| Unit | Deleted/Reduced Topics |
|---|---|
| Chemical Reactions | Corrosion and rancidity (reduced — only definitions, no detailed mechanisms) |
| Carbon Compounds | Nomenclature of carbon compounds with more than 5 carbons, cleansing action of soaps and detergents (detailed mechanism deleted) |
| Life Processes | Detailed mechanism of autotrophic nutrition (only summary required), transportation in plants (reduced) |
| Our Environment | Ozone layer depletion (reduced), management of natural resources (entire chapter reduced) |
| Electricity | Electric power in detail (formula retained, derivation deleted) |
Social Science
| Subject | Deleted/Reduced Topics |
|---|---|
| History | Chapter: The Age of Industrialisation (reduced), Chapter: Print Culture and the Modern World (may be reduced or for self-study) |
| Geography | Minerals and Energy Resources (reduced content), Manufacturing Industries (reduced) |
| Political Science | Chapter: Political Parties (reduced — only key concepts), Challenges to Democracy (reduced) |
| Economics | Consumer Rights (may be for self-study only) |
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Physics
| Chapter | Deleted/Reduced Topics |
|---|---|
| Electric Charges & Fields | Continuous charge distribution (reduced) |
| Electromagnetic Waves | Displacement current (derivation deleted, concept retained) |
| Communication Systems | Entire chapter deleted from board exam syllabus |
| Semiconductor | Reduced — only p-n junction, diode characteristics, LED, solar cell. Transistor as amplifier and oscillator deleted. |
Chemistry
| Chapter | Deleted/Reduced Topics |
|---|---|
| Solid State | Electrical and magnetic properties of solids, band theory |
| Solutions | Abnormal molecular mass (detailed — only concept mentioned) |
| Surface Chemistry | Catalysis in detail, enzyme catalysis, colloids (reduced) |
| Chemistry in Everyday Life | Entire chapter deleted or reduced to self-study |
| Polymers | Biodegradable polymers (detailed content reduced) |
Mathematics
| Chapter | Deleted/Reduced Topics |
|---|---|
| Relations & Functions | Composition of functions (reduced), binary operations |
| Inverse Trigonometric Functions | Properties of inverse trig (reduced — only principal values) |
| Determinants | Properties of determinants (some advanced properties deleted) |
| Linear Programming | Entire chapter deleted from board exam syllabus |
Biology
| Chapter | Deleted/Reduced Topics |
|---|---|
| Reproduction in Organisms | Vegetative propagation in detail (reduced to examples only) |
| Environmental Issues | Detailed case studies deleted, only key concepts retained |
| Strategies for Enhancement in Food Production | Reduced or for self-study |
Deleted vs Retained — What It Means for You
| Category | What It Means | Action |
|---|---|---|
| Deleted for Assessment | Will NOT appear in board exams | Do not study for boards. May still be in JEE/NEET syllabus. |
| Retained | Will appear in board exams | Prepare thoroughly. All exam questions come from here. |
| Self-Study | Not in board exam, but mentioned in syllabus for learning | Skim for general knowledge. Not exam-critical. |
| Reduced | Partial content deleted, key concepts retained | Focus on retained portions only. Check syllabus document carefully. |
Important Warning for JEE/NEET Students
CBSE deleted syllabus ≠ JEE/NEET deleted syllabus. These are different exams with different syllabuses.
- Communication Systems — deleted from CBSE Physics but check JEE Main syllabus
- Linear Programming — deleted from CBSE Maths but was in JEE Main previously
- Chemistry in Everyday Life — deleted from CBSE but may appear in NEET
- Always cross-check with the official JEE Main / NEET information bulletin on NTA's website
- When in doubt, prepare the topic — it is better to over-prepare than miss questions
Deleted topics based on CBSE Rationalised Syllabus 2025–2026 published on cbseacademic.nic.in. CBSE may update the syllabus — always verify with the official document. This page lists key deletions, not all deletions. Download the complete subject-wise document for your stream. Last updated: February 2026.
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Start preparing — freeFrequently Asked Questions
Where can I find the official CBSE deleted syllabus?
The official deleted/rationalised syllabus is available on cbseacademic.nic.in → Curriculum → Rationalised Syllabus. CBSE publishes the complete syllabus document with retained and deleted portions clearly marked. Always download from cbseacademic.nic.in — this is the only authentic source.
Will deleted topics appear in the board exam?
No. Deleted topics will NOT appear in the CBSE board exam. CBSE has confirmed that questions will only be asked from the retained syllabus. However, for competitive exams (JEE Main, NEET, CUET), some deleted CBSE topics may still be in the exam syllabus — always check the competitive exam's own syllabus separately.
Are deleted topics important for JEE/NEET?
Possibly yes. JEE Main and NEET follow their own syllabus (set by NTA), which may include topics deleted from CBSE curriculum. For example, some topics removed from CBSE Physics/Chemistry may still appear in JEE Main. Always cross-check with the JEE/NEET information bulletin. If a topic is in the NTA syllabus, prepare it regardless of CBSE deletion.
Does CBSE delete syllabus every year?
CBSE rationalised the syllabus significantly during COVID (2020–2022) by removing 30%. Since then, some topics have been permanently removed while others were restored. CBSE reviews and updates the curriculum periodically. The 2025–2026 rationalised syllabus was published in April 2025. Check cbseacademic.nic.in for the latest version.
Should I study deleted topics for internal assessment?
No. Internal assessment is also based on the retained syllabus only. Your school projects, practicals, and internal tests should focus on the prescribed syllabus. If your school teacher includes deleted topics in class tests, politely point out that these are not in the CBSE exam syllabus.
Is the deleted syllabus the same for all streams?
No. Each subject has its own list of deleted topics. Science stream (PCM/PCB), Commerce, and Arts subjects all have different deletions. Download the subject-specific syllabus document from cbseacademic.nic.in to see exactly which topics are removed for YOUR subjects.