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 2025 ( IISER Entrance Exam )

Manisha
Manisha Kumari
Associate Senior Executive
Updated on May 25, 2025 13:40 IST

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 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.

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 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.

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Q:   How many sections are asked in the IISER Entrance Exam?
A:

The IISER Entrance Exam 2025 pattern has already announced. IISER Entrance Exam 2025 pattern remains to be same as of the previous year of IISER Entrance Exam which was also conducted in online mode I. e. computer-based. IAT consist of 60 questions, 15 questions each from Biology Chemistry Mathematics, and Physics. Total time for answering the test was 180 minutes. Questions were multiple choice type with only one correct answer.

Q:   What are the types of questions asked in the IISER 2025 exam?
A:

The IISER Entrance Exam questions are objective and carries multiple choices (MCQs). Each question has four answer options. Candidates have to deduce the correct answer option and click on it with the help of mouse. Since IISER 2025 exam is conducted in a computer-based mode, test-takers will be able to mark only one answer option. 

Q:   When will IAT 2025 Student Response Sheet release?
A:

Indian Institutes of Science Education and Research (IISER), the examination conducting body already released the IISER Aptitude Test (IAT) 2025 Student Response Sheet on second week of June 2025. Candidates can visit the official website of IISER and after logging in with their credentials can finally view their IAT 2025 Response Sheet. Candidates can finally tally up their marks scored in the IISER Aptitude Test which conducted in the first week of June 2025. 

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.

Table of content
  • 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.

Check out the IISER Entrance Exam 2025 Student Reaction Video from here:

 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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About the Author
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Manisha Kumari
Associate Senior Executive
Being a post-graduate and BEd degree holder, I'm an innovative, task-driven and immensely motivated science enthusiast, making me a passionate content writer. I love providing meaningful and constructive articles in Read Full Bio
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Answered 2 months ago

With a 7,000 rank in the SC category, admission to any IISER (including newer campuses) is not possible as per 2025 cutoffs. Cutoff ranks for SC category in IISERs generally close between 125 (most competitive) and 750 (least competitive).

P

PRINCE MISHRA

Contributor-Level 7

Answered 2 months ago

IISER Berhampur cutoff 2025 for the BS + MS course across multiple specialisations stood at 3299 during the Round 1 cutoff for the students belonging to the General AI quota. So, considering the first-round cutoff rank, candidates must target to secure a rank up to 3299 and lower to improve their ch

...Read more

R

Rashmi Sinha

Contributor-Level 10

Answered 2 months ago

IISER Mohali cutoff 2025 has been released for different categories of students under the AI quota. For the General category, the cutoff rank for BS + MS admission across multiple specialisations was 1778. To view the category-wise ranks, refer to the table below:

CategoryBS + MS
General1778
OBC1358
SC520
ST263
EWS480
PWD50112

R

Rashmi Sinha

Contributor-Level 10