All 85 decoded questions of ESAT 2020, in paper order. · A question can reward more than one move, so the counts overlap.
ENGAA 2020 Section 1, Part B (Mathematics questions) 20 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
61 Prokaryote versus eukaryote: the defining feature contrast (wall, nucleus, mitochondria, chloroplasts) Pavlov Biology Cells 5 other sittings Same method, other sittings
62 Phenotype comes from genotype and environment together, beware the alone trap Key method Biology Inheritance, Variation & Evolution 2 other sittings Same method, other sittings
63 Carbon cycle diagrams: follow the arrows and check each product for carbon and hydrogen Key method Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
64 DNA base arithmetic: pairing rules bind the whole molecule, never a single strand Key method Biology DNA, Protein Synthesis & Gene Technology 3 other sittings Same method, other sittings
65 Temperature and pH curves peak at an optimum; a concentration curve plateaus An enzyme is a protein catalyst, not a living thing: eliminate options that contradict its nature Key method Biology Enzymes 3 other sittings Same method, other sittings
66 Mitosis keeps the chromosome number and makes two cells, meiosis halves it and makes four Key method Biology Membrane Transport, Cell Division & Reproduction 6 other sittings Same method, other sittings
67 Could, may or might means find one valid scenario, not prove it always holds Genetic engineering means moving or altering a gene; cloning a whole nucleus does not Somatic changes are not inherited; only gamete (germline) changes reach offspring Key method Biology DNA, Protein Synthesis & Gene Technology 4 other sittings Same method, other sittings
68 Read a tissue or organ from the difference between blood entering and leaving it Key method Biology Animal Physiology: Systems, Homeostasis & Disease 1 other sitting Same method, other sittings
69 Natural selection edits pre-existing random variation, the environment never writes it Heterozygote advantage keeps a harmful recessive allele in a population under pressure Key method Biology Inheritance, Variation & Evolution 4 other sittings Same method, other sittings
70 Weigh the modal word: always or must needs certainty, could or may needs only one plausible mechanism Oxygen sag below organic pollution: bacteria strip the oxygen, and indicator species track the curve Key method Biology Ecology & Plant Physiology 5 other sittings Same method, other sittings
71 A rise-then-plateau curve means a factor is now limiting; plateau height is set by total substrate Temperature and pH curves peak at an optimum; a concentration curve plateaus Could versus must: separate what the data proves from what it only allows Key method Biology Enzymes 5 other sittings Same method, other sittings
72 The three osmosis definition traps examiners plant in statements Movement against the concentration gradient means active transport and needs energy Convert every quantity to one unit before comparing concentrations or sizes Key method Biology Membrane Transport, Cell Division & Reproduction 4 other sittings Same method, other sittings
73 Weigh the modal word: always or must needs certainty, could or may needs only one plausible mechanism Ecological abundance: frequency is presence in quadrats, density is count per area, and both need a random sample Key method Biology Ecology & Plant Physiology 5 other sittings Same method, other sittings
74 Volume in a capillary tube is a cylinder: pi times radius squared times length, radius is half the diameter Tunnel Biology Ecology & Plant Physiology 2 other sittings Same method, other sittings
75 Counter-current exchange keeps the donor above the receiver along the whole surface Key method Biology Animal Physiology: Systems, Homeostasis & Disease only this sitting Same method, other sittings
This one has only struck here so far.
76 Read the cardiac cycle by aligning ventricular volume with the ECG Key method Biology Animal Physiology: Systems, Homeostasis & Disease only this sitting Same method, other sittings
This one has only struck here so far.
77 Match each defence to its signature; antibiotics hit bacteria only, red cells are not phagocytic Pavlov Biology Animal Physiology: Systems, Homeostasis & Disease 1 other sitting Same method, other sittings
78 Osmosis moves water toward the more concentrated solution The cell wall decides whether a cell bursts, and the vacuole holds cell sap Pavlov Biology Membrane Transport, Cell Division & Reproduction 6 other sittings Same method, other sittings
79 Read dominance off the pedigree first, then fix which parents must be heterozygous Key method Biology Inheritance, Variation & Evolution 1 other sitting Same method, other sittings
80 A recessive phenotype fixes the genotype, a dominant phenotype needs a test cross Key method Biology Inheritance, Variation & Evolution 2 other sittings Same method, other sittings
NSAA 2020 Section 1 Part B (ESAT Physics) 18 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
41 Recall Group 1 and Group 17 trends whole, without deriving them Pavlov Chemistry Atomic Structure, Bonding & the Periodic Table 3 other sittings Same method, other sittings
42 Pick the separation technique from the property that differs Composition of dry air: 78% nitrogen, 21% oxygen, 1% argon Key method Chemistry Organic Chemistry, Separation & Analysis 3 other sittings Same method, other sittings
44 Standard qualitative tests to identify ions Pavlov Chemistry Organic Chemistry, Separation & Analysis 2 other sittings Same method, other sittings
45 An ionic formula must be charge neutral: cross the ion charges Pavlov Chemistry Chemical Reactions, Acids, Bases & Redox 1 other sitting Same method, other sittings
46 Balance a skeleton equation one element at a time, most constrained first Tunnel Chemistry Chemical Reactions, Acids, Bases & Redox 3 other sittings Same method, other sittings
47 Aqueous electrolysis discharge rules: below hydrogen deposits, halide gives the halogen Key method Chemistry Electrolysis & Metals 4 other sittings Same method, other sittings
48 Classify the structure and bonding, then read off the property Recall Group 1 and Group 17 trends whole, without deriving them Key method Chemistry Atomic Structure, Bonding & the Periodic Table 7 other sittings Same method, other sittings
49 Oxidation states sum to the overall charge, capped by the group number Key method Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
50 Rf equals spot distance over solvent-front distance Rf is fixed, so chromatogram distances scale with the front Pavlov Chemistry Organic Chemistry, Separation & Analysis 6 other sittings Same method, other sittings
51 Mass by difference: the component asked for is the leftover, and its molar mass is often a decoy Diprotic acid reflex: sulfuric and ethanedioic acid react two to one with a monobasic base Key method Chemistry Quantitative Chemistry 2 other sittings Same method, other sittings
52 Read the balanced equation directly in gas volumes, and track the change in the number of gas molecules Key method Chemistry Quantitative Chemistry 3 other sittings Same method, other sittings
53 Neutralisation counts protons and hydroxides per formula unit, not acid strength Key method Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
54 Read a rate-time curve as two separate things: plateau and steepness Key method Chemistry Rates of Reaction & Energetics 4 other sittings Same method, other sittings
55 Relative atomic mass as an abundance-weighted mean, forwards or reversed Back out the element from a given electron count, undoing the ionic charge first Tunnel Chemistry Atomic Structure, Bonding & the Periodic Table 6 other sittings Same method, other sittings
56 Combustion by general formula: balance carbon, then hydrogen, then oxygen, counting the fuel's own oxygen Tunnel Chemistry Chemical Reactions, Acids, Bases & Redox 2 other sittings Same method, other sittings
57 Calorimetry: q equals mc delta T, then divide by the limiting moles Thermometric graph: peak is neutralisation, the fall is only cooling Tunnel Chemistry Rates of Reaction & Energetics 3 other sittings Same method, other sittings
59 Diprotic acid reflex: sulfuric and ethanedioic acid react two to one with a monobasic base Pavlov Chemistry Quantitative Chemistry 2 other sittings Same method, other sittings
60 Electron accounting: turn charge into moles, then read every amount off the half-equations In amount MCQs the wrong options are the electron-count and diatomic-gas slips Tunnel Chemistry Electrolysis & Metals 4 other sittings Same method, other sittings
NSAA 2020 Section 1, Part A (Mathematics questions) 17 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
2 Simultaneous Linear Equations by Elimination Tunnel Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
3 Shaded areas by structural subtraction Pavlov Pure Geometry 2 other sittings Same method, other sittings
4 Systematic enumeration for small discrete sums Pavlov Prob & Stats Probability & Statistics 2 other sittings Same method, other sittings
5 Implicit line equations: isolate y to find the gradient safely Pavlov Pure Coordinate Geometry 3 other sittings Same method, other sittings
6 Successive percentage changes as a product of decimal multipliers Pavlov Pure Ratio & Proportion 5 other sittings Same method, other sittings
7 Quadratics in Disguise Key method Pure Algebra, Functions & Graphs 3 other sittings Same method, other sittings
9 Algebraic Fraction Simplification Pavlov Pure Algebra, Functions & Graphs 6 other sittings Same method, other sittings
10 Minimum of a Quadratic Pavlov Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
11 Setting up the proportionality constant Tunnel Pure Ratio & Proportion 5 other sittings Same method, other sittings
12 Convert means into absolute totals Pavlov Prob & Stats Probability & Statistics 4 other sittings Same method, other sittings
13 Chaining ratios by scaling the common term Pavlov Pure Ratio & Proportion 2 other sittings Same method, other sittings
14 Reverse percentage: divide by the final multiplier Pavlov Pure Ratio & Proportion 1 other sitting Same method, other sittings
15 Calculate the complement for at least one or complex conditions Key method Prob & Stats Probability & Statistics 1 other sitting Same method, other sittings
16 Overlay a coordinate system for complex intersecting shapes Key method Pure Geometry 5 other sittings Same method, other sittings
18 Root Gap from the Discriminant Key method Pure Algebra, Functions & Graphs 2 other sittings Same method, other sittings
19 3D solids: equating volumes and surface areas algebraically Tunnel Pure Geometry 5 other sittings Same method, other sittings
20 Coordinate transformations algebraically Key method Pure Geometry 3 other sittings Same method, other sittings
NSAA 2020 Section 1, Part C (Chemistry questions) 10 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
21 Factor and Remainder Theorem Pavlov Pure Algebra, Functions & Graphs 3 other sittings Same method, other sittings
23 Area Between Curves via Single Integral Tunnel Pure Integration 1 other sitting Same method, other sittings
25 Reflection in y=x swaps the coordinates Pavlov Pure Coordinate Geometry only this sitting Same method, other sittings
This one has only struck here so far.
27 Sums of Equal Blocks in an AP Key method Pure Sequences & Series only this sitting Same method, other sittings
This one has only struck here so far.
29 Areas bounded by intersecting lines: use an axis as the base Key method Pure Coordinate Geometry 3 other sittings Same method, other sittings
31 Discarding the Extraneous Root Key method Pure Sequences & Series 3 other sittings Same method, other sittings
33 Quadratic Derivative Conditions Pavlov Pure Differentiation 1 other sitting Same method, other sittings
35 Pythagorean Substitution to Quadratic Factor Out, Never Divide Key method Pure Trigonometry 3 other sittings Same method, other sittings
37 Substitute to a Polynomial (Exponentials & Logs) Tunnel Pure Exponentials & Logarithms 3 other sittings Same method, other sittings
39 Two-Stage Optimisation Key method Pure Differentiation only this sitting Same method, other sittings
This one has only struck here so far.
NSAA 2020 Section 1, Part D (Biology questions) 20 decoded 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.
21 Energy audit on a heated body: supplied, stored, lost The option list holds your intermediate results: never stop one step early Tunnel Physics Thermal Physics 2 other sittings Same method, other sittings
22 Atomic bookkeeping: protons are the element, neutrons are the isotope, electrons set the charge Key method Physics Radioactivity 2 other sittings Same method, other sittings
23 Sealed gas at constant temperature: density follows the pressure directly Constant temperature means the particle speeds are unchanged, only the collision rate moves Key method Physics Matter 2 other sittings Same method, other sittings
24 Across a boundary the frequency is fixed, so speed and wavelength change together Pavlov Physics Waves, Sound & the Electromagnetic Spectrum 2 other sittings Same method, other sittings
25 Alpha and beta decay bookkeeping: fix the alpha count from the mass number first Tunnel Physics Radioactivity 5 other sittings Same method, other sittings
26 Sort the three transfer modes by what each one actually requires Pavlov Physics Thermal Physics 2 other sittings Same method, other sittings
27 In a two state question, lock the invariant from state one before touching state two A closed ideal switch is a plain wire: redraw before you compute Transformers: voltage by turns ratio, current by power, never turns ratio for a non ideal current Key method Physics Electricity & Magnetism 5 other sittings Same method, other sittings
28 Read the option spread before computing: the distractors name the slip Key method Physics Electricity & Magnetism 4 other sittings Same method, other sittings
29 In a two state question, lock the invariant from state one before touching state two For a non ohmic component the graph is its Ohm law: the circuit picks the axis Key method Physics Electricity & Magnetism 6 other sittings Same method, other sittings
30 Force on a current: the work is deciding what B, I and L really are Key method Physics Electricity & Magnetism 4 other sittings Same method, other sittings
31 Classify a wave on the spectrum by converting band edges with the wave equation Tunnel Physics Waves, Sound & the Electromagnetic Spectrum 3 other sittings Same method, other sittings
32 In a collision momentum carries signs and kinetic energy does not Key method Physics Energy, Work & Momentum 2 other sittings Same method, other sittings
33 Read a motion graph by gradient and area, one phase at a time Answer only the phase the question names: every other phase area is an offered option Average force over a non-uniform phase is the momentum change divided by the time Tunnel Physics Kinematics & Forces 5 other sittings Same method, other sittings
34 When only a ratio is asked, form the ratio and let the unknowns cancel Prism with a hole: subtract in the cross-section, multiply by the length once Key method Physics Matter 4 other sittings Same method, other sittings
35 Read the period and wavelength off wave graphs as half-cycle steps and reduce fractional periods Key method Physics Waves, Sound & the Electromagnetic Spectrum 2 other sittings Same method, other sittings
36 Half-life arithmetic: work in powers of one-half, never in logarithms Count-rate questions: subtract the background before reading anything Pavlov Physics Radioactivity 6 other sittings Same method, other sittings
37 Free body first: list every force with its sign, then set the resultant equal to ma Steady motion is a free equation, and after a perturbation only the change is unbalanced Algebraic options: kill them by units, then by a limiting case, and never derive Tunnel Physics Kinematics & Forces 4 other sittings Same method, other sittings
38 Energy lost, wasted or done against drag is the input total minus the useful total Key method Physics Energy, Work & Momentum 3 other sittings Same method, other sittings
39 Springs: the extension is not the length, and the stored energy is half of what you expect Answers given as formulas: settle them by units and by which symbol already carries g Key method Physics Energy, Work & Momentum 3 other sittings Same method, other sittings
40 Which graph or what is happening: write the expression in each regime, then argue slope and curvature Key method Physics Kinematics & Forces 1 other sitting Same method, other sittings
