IISER 2025 Question Paper Analysis: IAT 2025 Answer Key (May 25), Diificulty Level & Expected Cut Off
Indian Institutes of Science Education and Research Entrance Exam 2026 ( IISER Entrance Exam )
Round 1 Counselling
24 Jul '26 - 28 Jul '26
IISER 2025 Question Paper and Answer Key PDF will be released on May 25, 2025, after the examination is successfully conducted. The exam will be held to test the candidate's domain knowledge in Physics, Mathematics, Biology and Chemistry. Read this Shiksha article to know IAT 2025 Question Paper Analysis and answer key details here.
IISER 2025 Exam Question Paper and Answer Key
IISER 2025 Exam was conducted successfully on May 25, 2025, from 9 am to 12 pm at various exam centres across the nation. Exam officials will test candidates domain knowledge in Chemistry, Biology, Physics and Mathematics in the form of MCQ questions for the duration of three hours.
The overall IAT 2025 exam difficulty level was moderate. Candidates who had opted for PCM found the Biology section tough to attempt, and candidates who had PCB in their class 12 found the Mathematics subject questions difficult to solve. Topics were equally distributed from the IAT 2025 syllabus. Preparation from NCERT Books will help the candidates to have a good IAT 2025 score.
The IAT 2025 question paper here in this article is designed after the IISER 2025 analysis and students' reactions. IISER 2025 questions have become very dynamic, and questions are more based on a practical and analytical approach than one-word answers. In the coming years, the questions will come from the disciplines, that are flourishing in the science domains, and there is no such need to mug up the concepts.
- ISER 2025 Question Paper and Answer Key
- IISER 2025 Exam Analysis
- IISER 2025 Exam Difficulty Level
- IISER Entrance Exam 2025: Chapter Wise Weightage
- IISER 2025 Expected Cut Off
ISER 2025 Question Paper and Answer Key
The exam officials will be releasing the IAT 2025 answer key on the official website. Candidates can check the 2025 question paper and answer key from the below-mentioned link.
| IISER 2025 Question Paper & Answer Key |
Available Soon |
IISER 2025 Exam Analysis
Based on the student reactions, IISER 2025 overall exam difficulty level was moderate. Candidates who are from PCB stream found Biology very easy and took more time for Mathematics questions. Equal distribution of subjects and topics was found in the exam. Both the practical and theory-based questions were asked by the exam officials. Many of the students found the physics section as the most difficult section to attend. Questions in physics were mostly application-based based and the electricity topic had the highest weightage of questions.
Questions in biology were technical and practical-based; no repeated questions were asked in this section.
IISER 2025 Exam Difficulty Level
Candidates can check out the IISER 2025 exam difficulty level from here:
| Subject |
Difficulty Level |
Good Attempt |
|---|---|---|
| Biology |
Easy |
12-13 Questions |
| Physics |
Moderate to Difficult |
8-10 Questions |
| Chemistry |
Moderate |
10-12 Questions |
| Mathematics |
Easy to Moderate |
10-12 Questions |
Check out the overall exam difficulty level of IAT 2025 based on Student Reactions:
| Difficulty Level | Percentage |
|---|---|
| Easy | 18% |
| Moderate | 64% |
| Tough | 18% |
IISER Entrance Exam 2025: Chapter Wise Weightage
Check out the IISER exam 2025 chapter wise weighatge of Mathematics, Physics, Chemistry and Biology subjects from here:
Physics Chapter-wise Weightage
| Chapter |
Approx. No. of Questions |
|---|---|
| Kinematics |
1–2 |
| Laws of Motion |
1–2 |
| Work, Energy & Power |
1 |
| Rotational Motion |
1 |
| Thermodynamics |
1–2 |
| Oscillations & Waves |
1 |
| Electrostatics |
1 |
| Current Electricity |
1–2 |
| Magnetism & EMI |
2 |
| Optics |
1–2 |
| Modern Physics (Atoms/Nuclei) |
1–2 |
Chemistry Chapter-wise Weightage
| Chapter |
Approx. No. of Questions |
|---|---|
| Atomic Structure |
1 |
| Chemical Bonding |
1–2 |
| Thermodynamics |
1 |
| Equilibrium |
1–2 |
| Redox Reactions & Electrochem. |
1 |
| Chemical Kinetics |
1 |
| Organic Chemistry – Basics |
1–2 |
| Hydrocarbons & Functional Grps |
2–3 |
| Coordination Compounds |
1 |
| Biomolecules |
1 |
Mathematics Chapter-wise Weightage
| Chapter |
Approx. No. of Questions |
|---|---|
| Sets, Relations & Functions |
1 |
| Trigonometry |
1 |
| Algebra (Complex, Quadratics) |
2 |
| Calculus (Limits, Derivatives) |
2–3 |
| Integrals & Applications |
1–2 |
| Vectors & 3D Geometry |
2 |
| Probability |
1–2 |
| Matrices & Determinants |
1 |
Biology Chapter-wise Weightage
| Chapter |
Approx. No. of Questions |
|---|---|
| Cell Structure & Function |
1–2 |
| Genetics & Evolution |
2–3 |
| Human Physiology |
3–4 |
| Plant Physiology |
2 |
| Reproduction |
1 |
| Biotechnology |
1 |
| Ecology |
2 |
| Diversity of Life/Structural Org. |
1 |
IISER 2025 Expected Cut Off
IAT 2025 candidates' ranks will be based on their combined scores from the four sections (Physics, Chemistry, Mathematics and Biology). The exam comprises 60 questions with a total score of 240 marks. Below is a table for the expected IISER 2025 ranks corresponding to different score ranges.
| IISER 2025 Score (Out of 240) |
Expected IISER 2025 Rank |
|---|---|
| 200 and above |
Rank 1 to 80 |
| 200-160 |
Rank 81- 200 |
| 160- 110 |
Rank 201 to 800 |
| 110-95 |
Rank 800 to 1500 |
| 95-75 |
Rank 1500- 2000 |
| < 60 |
Above 2000 |
Also Read: IISER 2024 Marks vs Rank: Check Cut off and Opening- Closing Ranks
IISER 2024 Question Paper and Answer Key
The exam officials have released the IAT 2024 answer key on the official website. Candidates can also check the 2024 question paper and answer key from the below-mentioned link. Candidates must note that option A of the released questions paper is the correct answer in the PDF.
Download IAT 2024 Question Paper and Answer Key Here:Download Now
Read More: IISER Question Paper Analysis (OUT): IAT 2024 Answer Key Released
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Student Forum
Anything you would want to ask experts?Answered a month ago
Yes, you can get admission to the IISER with 6000 rank. However, admission will depend on your category. SC/ST category students have a strong chance of admisison with the mentioned rank. General category students can get admission to the newly added IISER.
V
Contributor-Level 10
Answered a month ago
In such a situation, you have to prioritise which exam you want to appear for. You might have prepared for months for the exam. Based on your preparation, you have to decide which exam you can easily qualify for and get admission to the desired course and college.
V
Contributor-Level 10
Answered a month ago
Yes, the IAT response sheet for 2026 is officially out. You can check your response sheet on the official IISER admissions portal through your login credentials.
S
Contributor-Level 6
Answered 2 months ago
Students can create an IISER login id and password during registration. The details required to register for IISER are Name, Date of birth, gender, citizenship status, mobile number, and email address.
V
Contributor-Level 10
Answered 2 months ago
No, IISER registration was over on April 13, 2026. Students were able to register for IAT 2026 from March 5 to April 13.
V
Contributor-Level 10
Answered 2 months ago
IAT user id is (application number / registration number). It is created during the IISER registration process. After the registration is over, user id and password are sent to the registered email address and mobile number.
V
Contributor-Level 10