IAT 2025 Paper Analysis – Subject-wise Trends & Question Weightage
This page presents a comprehensive analysis of the IAT 2025 question paper, highlighting subject-wise question distribution, chapter-level weightage, and observable trends in the IISER Aptitude Test.
Unlike isolated year reviews, this analysis places IAT 2025 in the context of recent exam patterns to help aspirants understand how preparation strategies need to evolve.
Overall Nature of the IAT 2025 Paper
The IAT 2025 paper followed the standard four-subject structure, with equal representation from Biology, Chemistry, Mathematics, and Physics. The paper leaned towards conceptual clarity and application rather than formula-heavy or memory-based questions. Students found Physics to be the most challenging (application-based) while Biology was often considered easier. Mathematics was moderate to difficult, and Chemistry was generally moderate.
Difficulty perception can vary depending on subject strength and preparation depth.
Subject-wise Question Distribution in IAT 2025
| Subject | No. of Questions | Approx. Weightage | General Difficulty |
|---|---|---|---|
| Biology | 15 | ~25% | Easy to Moderate |
| Chemistry | 15 | ~25% | Moderate |
| Mathematics | 15 | ~25% | Moderate |
| Physics | 15 | ~25% | Moderate to Hard |
IISER continues to maintain equal subject weightage across all sections.
Biology – IAT 2025 Chapter-wise Analysis
The Biology section in IAT 2025 included 15 questions, with emphasis on Genetics, Cell Biology, Plant Physiology, and Human Physiology. Most questions were directly aligned with NCERT concepts.
| Chapter | No. of Questions |
|---|---|
| Principles of Inheritance and Variation | 2 |
| Biotechnology: Principles and Processes | 1 |
| Molecular Basis of Inheritance | 1 |
| Biomolecules | 1 |
| Photosynthesis in Higher Plants | 1 |
| Sexual Reproduction in Flowering Plants | 1 |
| Animal Kingdom | 1 |
| Respiration in Plants | 1 |
| Excretory Products and their Elimination | 1 |
| Cell: The Unit of Life | 1 |
| Locomotion and Movement | 1 |
| Ecosystem | 1 |
| Breathing and Exchange of Gases | 1 |
| Total | 15 |
Chapters such as Human Health and Disease, Evolution, Organisms and Populations, Structural Organisation in Animals, Body Fluids and Circulation, Morphology and Anatomy of Flowering Plants, Human Reproduction, Biodiversity and Conservation, Neural Control and Coordination, Microbes in Human Welfare, Biotechnology and its Applications, The Living World, Reproductive Health, and other zero-weightage topics did not contribute questions in IAT 2025.
Score Maximum in Biology – Tip
Biology has been an easy-scoring subject in the IAT for years. Strengthen your Biology preparation to gain an edge and improve your chances of getting into top IISERs.
Chemistry – IAT 2025 Chapter-wise Analysis
The Chemistry section in IAT 2025 consisted of 15 questions, with noticeable representation from Physical Chemistry and key chapters of Organic and Inorganic Chemistry. Compared to the previous year, numerical problem-solving had slightly higher presence.
| Chapter | No. of Questions |
|---|---|
| Chemical Bonding and Molecular Structure | 2 |
| Aldehydes, Ketones and Carboxylic Acids | 2 |
| Electrochemistry | 2 |
| The Coordination Compounds | 1 |
| Structure of Atom | 1 |
| Thermodynamics | 1 |
| Chemical Kinetics | 1 |
| Amines | 1 |
| Hydrocarbons | 1 |
| Biomolecules | 1 |
| d- and f-Block Elements | 1 |
| Alcohols, Phenols and Ethers | 1 |
| Total | 15 |
Chapters such as Haloalkanes and Haloarenes, Equilibrium, Redox Reactions, Solutions, Classification of Elements and Periodicity in Properties, Organic Chemistry – Some Basic Principles and Techniques, and Some Basic Concepts of Chemistry did not contribute questions in IAT 2025.
Mathematics – IAT 2025 Chapter-wise Analysis
The Mathematics section in IAT 2025 contained 15 questions, with a strong emphasis on Calculus and selected topics from Algebra and Coordinate Geometry. Several questions required multi-step logical reasoning.
| Chapter | No. of Questions |
|---|---|
| Application of Derivatives | 2 |
| Conic Sections | 1 |
| Integrals | 1 |
| Complex Numbers and Quadratic Equations | 1 |
| Matrices | 1 |
| Differential Equations | 1 |
| Sequences and Series | 1 |
| Continuity and Differentiability | 1 |
| Permutations and Combinations | 1 |
| Determinants | 1 |
| Vector Algebra | 1 |
| Probability | 1 |
| Straight Lines | 1 |
| Inverse Trigonometric Functions | 1 |
| Total | 15 |
Chapters such as Relations and Functions, Sets, Trigonometric Functions, Binomial Theorem, Linear Programming, Linear Inequalities, Statistics, Three-Dimensional Geometry, Limits and Derivatives, and other zero-weightage or deleted topics were not represented in IAT 2025.
Physics – IAT 2025 Chapter-wise Analysis
The Physics section in IAT 2025 consisted of 15 questions, with relatively higher weightage for Electrostatics, Rotational Mechanics, and Waves. The paper tested conceptual clarity across classical and modern physics.
| Chapter | No. of Questions |
|---|---|
| Electrostatic Potential and Capacitance | 2 |
| Systems of Particles and Rotational Motion | 2 |
| Waves | 2 |
| Work, Energy and Power | 1 |
| Ray Optics and Optical Instruments | 1 |
| Dual Nature of Radiation and Matter | 1 |
| Moving Charges and Magnetism | 1 |
| Electromagnetic Induction | 1 |
| Atoms | 1 |
| Thermal Properties of Matter | 1 |
| Wave Optics | 1 |
| Magnetism and Matter | 1 |
| Total | 15 |
Chapters such as Units and Measurement, Laws of Motion, Motion in a Plane, Gravitation, Current Electricity, Alternating Current, Kinetic Theory, Nuclei, Electromagnetic Waves, Semiconductor Electronics, Mechanical Properties of Solids and Fluids, and other zero-weightage topics were not represented in IAT 2025.
IAT 2024 vs IAT 2025 – Subject-wise Comparison
Comparing IAT 2024 and IAT 2025 provides useful insight into how the IISER Aptitude Test is evolving while maintaining its core structure.
| Aspect | IAT 2024 | IAT 2025 |
|---|---|---|
| Overall Paper Nature | Balanced with moderate difficulty | Conceptual with increased application-based questions |
| Biology Focus | Genetics and Biotechnology dominated | Genetics and Cell Biology remained important |
| Chemistry Focus | Coordination Compounds and Organic Chemistry | Greater emphasis on Physical Chemistry numericals |
| Mathematics Focus | Calculus and Coordinate Geometry | Higher weightage to Application of Derivatives |
| Physics Focus | Oscillations had highest weightage | Electrostatics, Rotational Motion, and Waves dominated |
| NCERT Dependence | Strong NCERT alignment | Strong NCERT alignment with deeper application |
While the overall structure remained consistent, IAT 2025 showed subtle shifts in chapter emphasis across subjects.
Key Signals for IAT 2026 Aspirants
Analysis of the IAT 2024 and IAT 2025 papers reveals several important signals that aspirants should consider while preparing for IAT 2026.
- Equal importance to all four subjects continues, making balanced preparation essential.
- Conceptual clarity over rote learning is consistently rewarded, especially in Biology and Chemistry.
- Calculus and application-based problems remain critical in Mathematics.
- Core Physics chapters such as Electrostatics, Rotational Motion, Oscillations, and Waves should be prioritised.
- NCERT textbooks remain the foundation across all subjects, with emphasis on understanding rather than memorisation.
Aspirants should use recent year analyses to refine preparation strategies rather than relying solely on older exam trends.
Master the Core Concepts – Tip
The exam pattern may change a bit every year, with the focus shifting between topics. So it’s best to strengthen your core concepts and practice as many related questions as you can. Try solving IAT-style mock tests regularly
IAT Over The Years
Click on any year below to view the complete subject-wise analysis and insights.
Baseline year with strong emphasis on calculation-heavy questions, especially in Physics and Mathematics.
View full analysis → 2023Transition year showing more balanced chapter distribution and early signs of application-based questioning.
View full analysis → 2024Balanced paper with equal subject weightage and consistent alignment with NCERT concepts.
View full analysis → 2025Application-oriented paper with increased emphasis on conceptual depth and real problem-solving.
FAQs on IAT 2025 Paper Analysis
How was the difficulty level of IAT 2025?
The overall difficulty level of IAT 2025 can be described as balanced, with variations across subjects depending on conceptual depth. Students found Physics to be the most challenging (application-based) while Biology was often considered easier. Mathematics was moderate to difficult, and Chemistry was generally moderate.
What was the toughest subject in IAT 2025?
Based on student feedback and the nature of questions asked, Physics was considered the toughest subject in IAT 2025. Many questions were application-based and required strong conceptual clarity, particularly from Electrostatics, Rotational Motion, and Waves.
What was the easiest subject in IAT 2025?
Biology was often considered the easiest subject in IAT 2025, as most questions were directly aligned with NCERT concepts and involved limited numerical or multi-step reasoning.
What were the easy scoring topics asked in IAT 2025?
Easy scoring topics in IAT 2025 included Genetics-related chapters in Biology, Coordination Compounds and Aldehydes, Ketones and Carboxylic Acids in Chemistry, and selected theory-based questions from Modern Physics.
What were the most weightage topics in IAT 2025?
High-weightage topics in IAT 2025 included Electrostatic Potential and Capacitance, Systems of Particles and Rotational Motion, and Waves in Physics, Application of Derivatives in Mathematics, Chemical Bonding and Electrochemistry in Chemistry, and Principles of Inheritance and Variation in Biology.
Was IAT 2025 similar to IAT 2024?
While the overall structure remained consistent, IAT 2025 showed subtle shifts in chapter emphasis, indicating evolving exam trends.
Is IAT 2025 analysis useful for IAT 2026 preparation?
Yes, understanding the trends and focus areas in IAT 2025 helps aspirants align preparation with the most recent exam patterns.
