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IAT (IISER) 2026

Browse the complete Biology, Chemistry, Mathematics, and Physics question set from the IAT (IISER) 2026 paper, question by question. Each question shows a quick preview so you can jump straight to the topic or subject you want to revise. Click through to attempt the full question in practice mode, or head back to the paper-wise list to download the entire paper as a PDF.

This paper has 56 questions in total - 8 easy (14%), 42 moderate (75%) and 6 tough (11%). That's a fairly typical mix for this exam. By subject: Biology 13% easy, 87% moderate, 0% tough; Chemistry 8% easy, 69% moderate, 23% tough; Mathematics 15% easy, 85% moderate, 0% tough; Physics 20% easy, 60% moderate, 20% tough.

Biology questions were spread across 13 chapters, with Body Fluids and Circulation (2), Molecular Basis of Inheritance (2), and Anatomy of Flowering Plants (1) carrying the most weight. Chemistry questions were spread across 10 chapters, with Chemical Bonding and Molecular Structure (2), Coordination Compounds (2), and General Organic Chemistry (2) carrying the most weight. Mathematics questions were spread across 12 chapters, with Continuity and Differentiability (2), Binomial Theorem (1), and Complex Number (1) carrying the most weight. Physics questions were spread across 12 chapters, with Dual Nature of Matter (2), Electrostatics (2), and Oscillations (2) carrying the most weight.

Biology

  1. 1Which of the following processes result in development of a proton gradient across the thylakoid membrane during photosynthesis? i. Release 2026Mechanism of Photosynthesis
  2. 2Which one of the following choices matches the organs in column I with their vascular system arrangement described in column II? Column I Co2026Anatomy of Plant Parts
  3. 3The graphs below depict the number of individuals of two organisms, named P and Q, when grown independently, and together. Based on these gr2026Populations
  4. 4The pBR322 cloning vector has genes coding for tetracycline and ampicillin resistance. A foreign DNA to be cloned is inserted into the tetra2026Tools of Recombinant DNA Technology
  5. 5For which one of the following enzyme activity plots, will the of the enzyme for substrate 'S' be 20? [S] indicates substrate concentration.2026Enzymes
  6. 6Which one of the following correctly describes the mode of action of Follicle Stimulating Hormone (FSH) and estrogen?2026Introduction
  7. 7If cell wall was used as the only criterion for classifying organisms, then Mycoplasma would have belonged to which one of the following gro2026Introduction
  8. 8Which one of the following is the correct sequence of the coding strand of the given gene?2026Transcription
  9. 9Which one of the following correctly describes the sequence of events leading to muscle contraction following acetylcholine release at the n2026Locomotion
  10. 10In which one of the following cases, will an anti-Rh antibody treatment prevent erythroblastosis foetalis ?2026Blood Group
  11. 11Which of the following schematics correctly depict a lac operon that can be negatively regulated?2026Regulation of Gene Expression
  12. 12For which one of the following parents, their children will NOT have the same blood group phenotype as either of the parents?2026Blood Group
  13. 13Which one of the following molecules can be used for RNA interference?2026Genetic Modified Crops
  14. 14The following pedigree diagram shows the inheritance of a rare genetic disorder in a family (filled shapes depict affected individuals). Whi2026Genetic Disorders
  15. 15A female child is born with all the primary oocytes required during her lifetime. At which one of the following stages of cell division are 2026Embryology

Chemistry

  1. 1Which one of the following octahedral complexes has the highest spin-only magnetic moment?2026Crystal Field Theory
  2. 2Which one of the following molecules shows an increase in bond order after loss of an electron from the highest occupied molecular orbital?2026Molecular Orbital Theory
  3. 3Metal-ligand -bond formation in and requires electron-pair donation between metal and ligand orbitals. Which one of the following represents2026Metal Carbonyls & Bonding in Metal Carbonyls
  4. 4What is the order of bond energy between C=S C=Te, and between Cl–Cl F–F?2026Covalent and Co-ordinate Bonding
  5. 5Which one is an INCORRECT statement with regard to the following reaction?2026Preparation and Properties of Monohalides
  6. 6Which one of the following molecules is chiral?2026Isomerism of Organic Compounds
  7. 7Consider the following silica-gel based thin-layer chromatogram of compounds A and B . Which one of the following statements is correct?2026Purification of Organic Compounds
  8. 8What are X and P in the following reaction sequence?2026Chemical reactions for aldehydes and ketones
  9. 9What is the order of for the following molecules in an aqueous medium?2026Preparation and Properties of Amines
  10. 10An ideal gas goes through a reversible isothermal expansion (solid line) followed by a reversible adiabatic expansion (dashed line). Which o2026First Law and Basic Fundamentals of Thermodynamics
  11. 11What is the ratio of the velocity of an electron in the fourth orbit of to the velocity of the electron in the second orbit of ?2026Bohr's model
  12. 12For two pure volatile liquids X and Y , attractive intermolecular interactions of both X - X and Y - Y are weaker than those of X - Y . The 2026Vapour pressure and raoult's law
  13. 13The rate constant of a reaction at 600 K with an activation energy of kJ mol is s . What is the temperature at which the half-life of the re2026Arrhenius theory

Mathematics

  1. 1Let be a quadratic polynomial such that . What is the coefficient of in ?2026Relation between Roots and Coefficients
  2. 2Consider the following sets of points in the complex plane and . Which of the following statements is TRUE?2026nth roots of unity
  3. 3Consider the points , and . Which of the following statements is TRUE?2026Algebra of Vectors
  4. 4Let be the line joining and and let be the line joining and . What is the angle between and ?2026Line in Space
  5. 5Let be two integers such that . What is the total number of functions such that are all distinct?2026Permutation
  6. 6What is the value of ?2026Properties of Definite Integration
  7. 7Consider the data of scores obtained by students in an examination. If the score of every student is increased by 2 marks, then which of the2026Measures of Dispersion
  8. 8For real numbers and , consider the function given by How many pairs are there for which is continuous at every point of ?2026Continuity
  9. 9For a matrix , whose elements are real numbers, denote by the product , where is a positive integer. Define , , , for all and , for all . Wh2026Product of Matrices
  10. 10Let be a geometric progression of positive integers such that and for all positive integers . What is the value of ?2026Geometric Progression
  11. 11Let . What is the remainder when is divided by 100?2026Remainder and Divisibility Problems
  12. 12Suppose there are two boxes and , each having 3 red and 4 black balls. One ball is drawn at random from . If it is red, 4 red balls are put 2026Conditional Probability and Multiplication Theorem
  13. 13Let be the function given by . What is the number of points where is NOT differentiable?2026Differentiability

Physics

  1. 1A sphere and a cube of equal masses on a horizontal frictionless floor, are confined between two vertical walls, as shown in the figure. The2026Time Period and Frequency
  2. 2A spherical concave mirror of focal length 10 cm and a double convex lens of focal length 5 cm are arranged on the common principal axis as 2026Combination of Lens and Mirrors
  3. 3A simple pendulum of length , mass and electric charge on its bob is oscillating with a time period under uniform gravity which is in the di2026Applications of SHM
  4. 4A particle of mass and electric charge starts from rest under the influence of a uniform external electric field to travel a distance in tim2026Electric Field and Electric Field Lines
  5. 5An exotic spherical jellyfish has a bulk modulus . Close to the surface of the sea (depth ), its radius is . When it dives to a depth ( ), i2026Bulk Modulus
  6. 6A planet is revolving in a circular orbit with a time period around the center of a star solely under the gravity of the star. Suppose the d2026Motion of satellite
  7. 7The position of a particle of mass 1 kg at time is given by , where is in seconds and the coefficients have the proper units for to be in me2026Angular momentum and Angular impulse
  8. 8A long solenoid of initial radius is put in a region of uniform magnetic field with the axis of the solenoid aligned along the magnetic fiel2026Magnetic Flux, Faraday's and Lenz law
  9. 9The acceleration of a point particle is given by the equation where denotes position and denotes time. Which of the following relations show2026Dimensions
  10. 10Consider normal incidence of a monochromatic beam of photons of power on a flat surface. Of the incident beam, 10% gets absorbed, 10% gets t2026Photoelectric Effect
  11. 11An experimental study of the photoelectric effect involves a metal of work function . What is the smallest wavelength of the incident photon2026Photoelectric Effect
  12. 12The three numbers: (number of protons, number of neutrons, the radius) characterize a nucleus. What is the value of for two nuclei character2026Nuclear structure
  13. 13A jar is filled with two monoatomic non-interacting gases and with total masses and , respectively. The molar mass of is double the molar ma2026Gas Laws
  14. 14Three infinite plane sheets which have uniform positive surface charge densities , and , are arranged parallel to each other with a separati2026Electric Flux and Gauss Law
  15. 15Consider two Carnot engines of efficiencies and . The first engine absorbs heat from a heat reservoir and releases heat to a heat reservoir 2026Heat Engine, Refrigerator andSecond Law of Thermodynamics

Frequently Asked Questions

1.How many questions are in the IAT (IISER) 2026 paper?

This paper has 56 questions in total - 15 from Biology, 13 from Chemistry, 13 from Mathematics, and 15 from Physics.

2.Can I practise questions from just one subject?

Yes. Use the Biology, Chemistry, Mathematics, and Physics tabs at the top of the page to jump directly to that subject's question set within this paper.

3.How is the IAT (IISER) 2026 paper structured?

The IAT (IISER) 2026 paper on MARKS has 56 questions, organised by subject:

  • Biology: 15 questions - 15 single-correct.
  • Chemistry: 13 questions - 13 single-correct.
  • Mathematics: 13 questions - 13 single-correct.
  • Physics: 15 questions - 15 single-correct.
4.How difficult is the IAT (IISER) 2026 paper?

Each question on MARKS carries a difficulty rating. Of the 56 rated questions in this paper, 8 (14%) are easy, 42 (75%) are medium and 6 (11%) are hard. Subject wise:

  • Biology: 2 easy, 13 medium, 0 hard
  • Chemistry: 1 easy, 9 medium, 3 hard
  • Mathematics: 2 easy, 11 medium, 0 hard
  • Physics: 3 easy, 9 medium, 3 hard
5.Which chapters were asked the most in the IAT (IISER) 2026 paper?

The chapters with the most questions in each subject were:

  • Biology: Body Fluids and Circulation (2) and Molecular Basis of Inheritance (2).
  • Chemistry: Chemical Bonding and Molecular Structure (2), Coordination Compounds (2), and General Organic Chemistry (2).
  • Mathematics: Continuity and Differentiability (2).
  • Physics: Dual Nature of Matter (2), Electrostatics (2), and Oscillations (2).
6.Where can I find the solutions for the IAT (IISER) 2026 paper?

Open any question on this page. Its page shows the correct answer and, where one is available, the worked solution. A downloadable PDF of the whole paper is coming soon.

7.How should I use the IAT (IISER) 2026 paper to check my preparation?

Set a timer, attempt the 56 questions as you would in the exam, and only then open the answers. Note which subjects and chapters cost you the most marks, and revise those first using the chapter-wise practice for IAT (IISER). Repeating this with other papers shows whether the same weak spots keep coming back.

8.Will the IAT (IISER) 2026 paper help me prepare for IAT (IISER) 2027?

Yes. Every past paper shows the question styles and topics IAT (IISER) has asked before, and a solved paper gives you a realistic benchmark for speed and accuracy. Use it along with the other papers to spot the chapters that keep returning.