Academic Session 2026-27

Tamil Nadu Board Class 11 Science Chapter Weightage 2026-27

Complete Mark Distribution for TNBSE Class 11 Science Subjects

Physics • Chemistry • Biology/Mathematics • Chapter-wise Marks • 70-80 Theory + 20-30 Internal

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4 Core Subjects 70-80 Theory Marks 20-30 Internal Marks 35% Passing Criteria

Chapter-wise Weightage for Science 2026-27

Detailed mark distribution for each subject to help you prioritize your exam preparation.

Physics - Chapter Weightage (80 Marks)

Unit	Topics Covered	Marks	Weightage
Mechanics	Motion in a Straight Line and Plane Laws of Motion - Newton's Laws, Friction Work, Energy and Power System of Particles - Centre of Mass Gravitation - Kepler's Laws	25	31.25%
Thermodynamics	Thermal Properties of Matter Thermodynamics - Laws, Heat Engines Kinetic Theory of Gases	15	18.75%
Waves & Oscillations	Oscillations - SHM, Simple Pendulum Waves - Wave Motion, Doppler Effect Properties of Waves	15	18.75%
Optics	Ray Optics - Reflection, Refraction Wave Optics - Interference, Diffraction Optical Instruments	12	15%
Modern Physics	Dual Nature of Matter and Radiation Atoms - Bohr Model Nuclei - Radioactivity Electronic Devices - Semiconductors	13	16.25%
Total		80	100%

Internal Assessment: 20 marks (Periodic Tests - 10, Notebook - 5, Practical - 5)

Chemistry - Chapter Weightage (70 Marks)

Unit	Topics Covered	Marks	Weightage
Physical Chemistry	Mole Concept and Stoichiometry Structure of Atom - Quantum Model Chemical Bonding - VSEPR Theory Thermodynamics - Laws, Enthalpy Equilibrium - Chemical & Ionic Redox Reactions	25	35.7%
Inorganic Chemistry	s-Block Elements - Alkali & Alkaline Earth p-Block Elements - Groups 13-18 Hydrogen - Properties, Hydrides Coordination Compounds	20	28.6%
Organic Chemistry	IUPAC Nomenclature Isomerism - Structural, Stereoisomerism Hydrocarbons - Alkanes, Alkenes, Alkynes Haloalkanes and Haloarenes Alcohols, Phenols and Ethers Aldehydes, Ketones and Carboxylic Acids Amines - Classification, Properties Biomolecules - Carbohydrates, Proteins	25	35.7%
Total		70	100%

Internal Assessment: 30 marks (Periodic Tests - 10, Notebook - 5, Practical - 10, Project - 5)

Biology - Chapter Weightage (70 Marks)

Unit	Topics Covered	Marks	Weightage
Plant Physiology	Plant Transport - Water and Mineral Uptake Photosynthesis - Light Reaction, Calvin Cycle Respiration in Plants - Glycolysis, Kreb's Cycle Plant Growth and Development - Hormones Mineral Nutrition - Essential Elements	20	28.6%
Animal Physiology	Digestion and Absorption Breathing and Exchange of Gases Body Fluids and Circulation - Blood, Heart Excretory Products - Urine Formation Locomotion and Movement Neural Control and Coordination Chemical Coordination - Endocrine System	25	35.7%
Genetics & Evolution	Principles of Inheritance - Mendelian Genetics Molecular Basis of Inheritance - DNA, RNA Evolution - Origin of Life, Natural Selection Genetic Disorders	15	21.4%
Ecology & Environment	Organisms and Populations - Factors Ecosystem - Structure, Energy Flow Biodiversity and Conservation Environmental Issues	10	14.3%
Total		70	100%

Internal Assessment: 30 marks (Periodic Tests - 10, Notebook - 5, Practical - 10, Project - 5)

Mathematics - Chapter Weightage (80 Marks)

Unit	Topics Covered	Marks	Weightage
Calculus	Limits and Derivatives Continuity and Differentiability Application of Derivatives - Maxima/Minima Integrals - Indefinite and Definite Application of Integrals - Area under Curves Differential Equations	25	31.25%
Algebra	Trigonometric Functions - Identities Complex Numbers and Quadratic Equations Permutations and Combinations Binomial Theorem Sequence and Series - AP, GP	20	25%
Vector & 3D Geometry	Vectors - Algebra, Dot and Cross Product 3D Geometry - Lines, Planes Linear Programming - Graphical Method	20	25%
Statistics & Probability	Statistics - Measures of Central Tendency Probability - Conditional, Bayes' Theorem Random Variables and Probability Distributions	15	18.75%
Total		80	100%

Internal Assessment: 20 marks (Periodic Tests - 10, Notebook - 5, Subject Enrichment - 5)

Smart Preparation Tips Based on Weightage

Focus on High-Weightage Topics

Prioritize units with higher marks like Mechanics in Physics (25 marks), Physical and Organic Chemistry (25 marks each), and Calculus in Mathematics (25 marks).

Balance Subjects Effectively

Allocate study time proportionally to the weightage of each subject. Physics and Mathematics need more problem-solving time.

Internal Assessment Matters

Don't ignore the 20-30 internal marks. Submit notebooks on time, participate in periodic tests, and complete practical work diligently.

Practice Competitive Exam Questions

Solve JEE/NEET level questions from high-weightage chapters. This helps in both school exams and competitive exams.

Frequently Asked Questions About Chapter Weightage

How is the chapter weightage useful for exam preparation?

Chapter weightage helps students prioritize their study time effectively. By knowing which chapters carry more marks, you can allocate more time to high-weightage topics while still covering all units. This strategic approach ensures better exam results with efficient preparation.

Does the chapter weightage change every year?

The chapter weightage is generally consistent year to year, but it's advisable to check the official TNBSE website for any updates. Minor changes may occur based on curriculum revisions.

What is the passing criteria for Class 11 Science?

Students must secure a minimum of 35% marks in each subject to be promoted to Class 12. This applies to both theory and internal assessment components combined. Failure in any subject may require compartmental examination.

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