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IAT (IISER) 2021

Browse the complete Biology, Chemistry, Mathematics, and Physics question set from the IAT (IISER) 2021 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 60 questions in total - 9 easy (15%), 46 moderate (77%) and 5 tough (8%). That's a fairly typical mix for this exam. By subject: Biology 47% easy, 53% moderate, 0% tough; Chemistry 7% easy, 93% moderate, 0% tough; Mathematics 0% easy, 80% moderate, 20% tough; Physics 7% easy, 80% moderate, 13% tough.

Biology questions were spread across 12 chapters, with Molecular Basis of Inheritance (2), Organisms and Populations (2), and Photosynthesis in Higher Plants (2) carrying the most weight. Chemistry questions were spread across 10 chapters, with Aldehydes and Ketones (2), Chemical Bonding and Molecular Structure (2), and Chemical Kinetics (2) carrying the most weight. Mathematics questions were spread across 14 chapters, with Area Under Curves (2), Application of Derivatives (1), and Continuity and Differentiability (1) carrying the most weight. Physics questions were spread across 14 chapters, with Capacitance (2), Dual Nature of Matter (1), and Electrostatics (1) carrying the most weight.

Biology

  1. 1Which one of the following epithelial cell types is commonly found in the inner surface of the fallopian tubes?2021Epithelial Tissue
  2. 2Which of the following is not an asexual reproductive structure?2021Types of Reproduction
  3. 3Which one of the following is an example of palindromic DNA sequence?2021Structure of DNA
  4. 4Some individuals start sneezing when the pollen content is high in the air. Primarily which Ig isotype will these individuals produce as an 2021Immune System Disorder
  5. 5Which of these factors is least likely to cause deviation from the Hardy-Weinberg equilibrium?2021Modern Theory of Evolution
  6. 6Motivated by the classic experiment by Frederick Griffith and the work of Avery, Macleod and McCarty to identify the transforming principle,2021The Search for Genetic Material
  7. 7Which of the following is/are produced by a plant during photosynthesis with far-red light?2021Mechanism of Photosynthesis
  8. 8The map of a 4000 base pair (bp) plasmid DNA marking the locations of different restriction enzyme cut sites is shown in the figure below. T2021Tools of Recombinant DNA Technology
  9. 9The following plot represents the change in the rate of photosynthesis with leaf temperature for two plants, P1 and P2. Which one of the fol2021Factor Affecting Photosynthesis
  10. 10The figure (i) represents two categories of animals ( X and Y ) with respect to their response to the external environment. The figure (ii) 2021Response to Abiotic Factors
  11. 11In plants, ammonium ions are produced by protonation of ammonia. Which enzyme uses these ammonium ions to convert an alpha-keto acid into an2021Nitrogen Metabolism
  12. 12Which one of the following physiological functions is common between the small intestine and the renal tubules?2021Absorption of Digestied Food
  13. 13Match the following pairs of interating species to the corresponding names of the interactions. Pick the correct option from below.2021Populations
  14. 14The following events are associated with meiosis: i) appearance of recombinant nodules ii) formation of meiotic spindle iii) formation of ch2021Meiosis
  15. 15Which of the following floral formulae represents a zygomorphic flower with diadelphous androecium and superior ovary?2021Technical Description of Angiosperm

Chemistry

  1. 1The F-P-Cl bond angles in the most stable structure of are close to2021Hybridisation and VSEPR Theory
  2. 2The correct statement about the bond angles and bond lengths in is terminal bridging Cl2021Hybridisation and VSEPR Theory
  3. 3Among and , which one is used to synthesize straight chain (lincar) and which one is used to prepare branched chain (cross-linked) silicone 2021Silicon and Its Compounds
  4. 4Which one of the following statements is INCORRECT about a complex of a divalent ion with atomic number 25 ?2021Werner's theory and Valence Bond Theory
  5. 5is diamagnetic because2021Werner's theory and Valence Bond Theory
  6. 6The correct order for the relative energies of the following sawhorse conformations is2021Isomerism of Organic Compounds
  7. 7Among the haloarenes (I-IV) shown below, the correct order of reactivity for the substitution reaction with NaOH is2021Preparation and Properties of Aryl Halides
  8. 8Consider the following reaction sequence, and identify the correct statements: (i) The products and can form addition product with HCN. (ii)2021Chemical reactions for aldehydes and ketones
  9. 9The major product of the reaction of salicylaldehyde with one equivalent of MeMgBr , followed by acid neutralization is2021Method of preparation for Ketones
  10. 10The total number of stereoisomers possible for the following structure is2021Isomerism of Organic Compounds
  11. 11For a homogeneous reaction involving ideal gases, equilibrium constants at are and . If the enthalpy change of the reaction is , the interna2021Law of Mass Action, Equilibrium Constant (Kc and Kp) and its Application
  12. 12The probability density of an electron in 1s orbital for an H atom is maximum2021Quantum mechanical model
  13. 13Which of the following statements is INCORRECT?2021Integrated rate laws
  14. 14The time required for reducing 1 mole of .) to .) when a current of is passed during electrolysis is2021Cells and Electrode Potential, Nernst Equation
  15. 15Based on the relative stabilities and barriers, which among the following schematic energy diagrams would best correspond to the reaction sc2021Arrhenius theory

Mathematics

  1. 1What is the maximum value of , when ?2021Maxima Minima
  2. 2Out of a pack of ten cards numbered 1 to 10, a boy draws a card at random and keeps it back. Then a girl draws a card at random from the sam2021Conditional Probability and Multiplication Theorem
  3. 3Suppose are such that the points , and in the coordinate plane are distinct, collinear, and the line passing through these points is not par2021Point and Line
  4. 4Define by . The area of the region is2021Area of Curve along axis
  5. 5The value of the limit is2021Special Forms
  6. 6Let be a continuous function satisfying Then which of the following is correct?2021Formation of Differential Equation
  7. 7For each , define Then, which one of the followings is true?2021Relation between Roots and Coefficients
  8. 8The number of functions such that for all , is2021Types of Function (Mapping)
  9. 9Let be two planes, and let denote the line of intersection of and . Let be the plane passing through the point , and normal to . Which of th2021Line in Space
  10. 10Let for . The value of is2021Properties of Definite Integration
  11. 11The area enclosed by the curves and the lines is2021Area of Curve along axis
  12. 12Consider the function defined by Then, which of the following statements is correct?2021Differentiability
  13. 13Let be a matrix such that Let denote the identity matrix. Which of the following statements is correct?2021Inverse of a Matrix
  14. 14If three real numbers are in arithmetic progression, the value of the determinant is2021Expansion of Determinants
  15. 15Consider the two data sets Let and be the means and the variances of and , respectively. Then, which of the following relations is correct?2021Mean

Physics

  1. 1A door of mass and width is hinged at one end and rotates about a vertical axis without friction. A bullet of mass fired perpendicularly to 2021Angular momentum and Angular impulse
  2. 2A body of mass executes simple harmonic motion along a line with time period and energy . What is the magnitude of the maximum acceleration 2021Simple Harmonic Motion
  3. 3An athlete runs on a straight track. She starts from rest and runs with a constant acceleration for the first 2 seconds, reaching a speed of2021Uniform Motion
  4. 4A capacitor of capacitance consists of two large parallel metal plates. The coefficient of linear expansion of the metal is . What is the ch2021Capacitance
  5. 5What are the charges stored in the and capacitors in the given circuit a long time after the key K is closed?2021Grouping of capacitors
  6. 6Consider a point charge moving with a constant velocity in vacuum in the presence of an electric field and a magnetic field . Unit vectors ,2021Motion of Charged Particle in Magnetic Field
  7. 7Four point charges and are placed at the four vertices of a regular tetrahedron of side , while a charge is placed at its center. What is th2021Electric Potential and Potential Energy
  8. 8The half life of a radioactive element is 2000 hours. Approximately how much time is required for the decay of of its nuclei?2021Radioactivity
  9. 9A 2-input exclusive OR (XOR) gate with inputs and produces the output . In the Boolean circuit shown below, which values of the inputs and w2021Logic gates
  10. 10In an experiment on the photoelectric effect, the de Broglie wavelength of the emitted electron is . The energy of the photon incident on th2021Photoelectric Effect
  11. 11An ambulance traveling at a speed emits a sound of frequency 540 Hz from its siren. Sunanda is driving a car which approaches the ambulance 2021Doppler's Effect
  12. 12Consider a Young's double slit experiment with monochromatic light of wavelength 600 nm . The intensity of the light is at a point on the sc2021Interference of Light
  13. 13Consider a mixture of and gases at temperature . Which of the following relations is correct?2021Speed of Gas
  14. 14Two identical objects A and B are at initial temperatures and , respectively. The specific heat capacity of the material of these objects in2021Calorimetry
  15. 15Which one of the following expressions has the dimension of electrical resistance where is the charge of an electron and is Planck's constan2021Dimensions

Frequently Asked Questions

1.How many questions are in the IAT (IISER) 2021 paper?

This paper has 60 questions in total - 15 each from Biology, Chemistry, Mathematics, and 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.What is the structure of the IAT (IISER) 2021 paper?

The IAT (IISER) 2021 paper on MARKS has 60 questions, organised by subject:

  • Biology: 15 questions - 15 single-correct.
  • Chemistry: 15 questions - 15 single-correct.
  • Mathematics: 15 questions - 15 single-correct.
  • Physics: 15 questions - 15 single-correct.
4.What is the difficulty level of the IAT (IISER) 2021 paper?

Each question on MARKS carries a difficulty rating. Of the 60 rated questions in this paper, 9 (15%) are easy, 46 (77%) are medium and 5 (8%) are hard. Subject wise:

  • Biology: 7 easy, 8 medium, 0 hard
  • Chemistry: 1 easy, 14 medium, 0 hard
  • Mathematics: 0 easy, 12 medium, 3 hard
  • Physics: 1 easy, 12 medium, 2 hard
5.Which chapters had the most questions in the IAT (IISER) 2021 paper?

The chapters with the most questions in each subject were:

  • Biology: Molecular Basis of Inheritance (2), Organisms and Populations (2), and Photosynthesis in Higher Plants (2).
  • Chemistry: Aldehydes and Ketones (2), Chemical Bonding and Molecular Structure (2), and Chemical Kinetics (2).
  • Mathematics: Area Under Curves (2).
  • Physics: Capacitance (2).
6.Where can I find the solutions for the IAT (IISER) 2021 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) 2021 paper to check my preparation?

Set a timer, attempt the 60 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) 2021 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.