Module 11 of 11Lesson 1 of 35 · 11.1 Inside the on-screen Physics exam: tasks, tools, timing and command terms
MYP Physics · Year 5 · Unit 11 · Lesson 1 · eAssessment bridge

Inside the on-screen Physics exam: tasks, tools, timing and command terms

Unit 11 eAssessment bridge · Lesson 1 of 5 · About 85 minutes · Key concept: Relationships · Related concepts: Evidence, Models · Global context: Scientific and technical innovation (how we adapt to and use digital tools) · eAssessment topics: the structure of the on-screen Physics examination (Criteria A, B, C and D, about 25 marks each, 120 minutes), item types and on-screen tools (calculator, formula sheet, symbols, table tool, graph plotter, drawing canvas, measuring tool, simulations), timing, command terms and what each demands, markscheme conventions (ECF, WTTE, ORA, independent unit marks) · This content carries forward unchanged into the Enhancing-MYP framework (first new-style eAssessment May 2030) · StadiraLab inside

By the end of this lesson you will be able to

  1. Describe the structure of the MYP Physics on-screen examination: 100 marks, 120 minutes, about 25 marks for each of Criteria A, B, C and D.
  2. Identify each on-screen tool and item type, and state the mistake that loses marks with each one.
  3. Plan your 120 minutes so that the design question and the long discuss-and-evaluate question get the time their marks deserve.
  4. Distinguish between the command terms used in Physics papers — state, outline, describe, explain, suggest, calculate, determine, justify, compare, evaluate, discuss — and answer at the depth each demands.
  5. Interpret markscheme conventions (ECF, WTTE, ORA, “unit awarded independently”, “do not accept”) and use them to mark your own work honestly.

You met this before

  • MYP sciences are assessed on four criteria: A Knowing and understanding, B Inquiring and designing, C Processing and evaluating, D Reflecting on the impacts of science, each judged on levels 0–8.
  • SI base units: metre (m), kilogram (kg), second (s), ampere (A), kelvin (K). Convert to base units before you substitute.
  • Prefixes: k (kilo) is 10³; M (mega) is 10⁶; m (milli) is 10⁻³; μ (micro) is 10⁻⁶; n (nano) is 10⁻⁹.
  • The independent variable is what you change; the dependent variable is what you read from an instrument; each control variable is kept at a stated value.
  • A mean is the sum of the trials divided by their number, rounded to the precision of the raw readings.
  • Every unit exam in this course (Units 1–10) used the same shape as the real paper: Task 1 Criterion A, Task 2 Criteria B and C, Task 3 Criterion D.
Quick retrieval

A trolley travels 1.20 m in 450 ms. Calculate its average speed in m s⁻¹, and state which quantity had to be converted first.

Reveal

450 ms = 0.450 s

v = d ÷ t

v = 1.20 m ÷ 0.450 s

v = 2.67 m s⁻¹ (3 significant figures, like the data)

The time had to be converted from milliseconds to seconds. The Physics May 2025 report named exactly this: “the time in milliseconds was commonly not converted to seconds”.

The puzzle

Two students sit the same Physics paper. On a quiz of definitions and equations they score the same.

One scores 76. The other scores 58. In May 2025 that was the gap between a grade 7 and a grade 5.

Neither knows more physics than the other. So where did 18 marks go?

The Physics reports answer this every session. Marks go on units left off, milliseconds not converted, “proportional” claimed for a curve, a table with units in every cell, and a discussion that stops without a conclusion. None of that is new physics. All of it is fixable.

Think first

Before reading on, predict three ways a student who knows the physics could still lose marks on the on-screen exam. Write them down, then compare.

Compare your answer

The reports list the same losses every session. A missing or wrong unit — the unit mark is often awarded separately, so “11.1” without “kW” drops a mark. A prefix not converted (nm, ms, km, days). Precision not matched: “20 instead of 20.0” (May 2025).

A command term ignored: a description where “explain” wanted a mechanism. A concluding appraisal missing: “a possible 2 marks” lost (May 2025). None of these is a gap in physics.

The science of the exam — structured notes

1.1 The paper at a glance: 100 marks, 120 minutes, four criteria

The MYP Physics eAssessment is one on-screen examination of 2 hours and 100 marks. It assesses all four criteria, each worth about a quarter of the marks: A Knowing and understanding, B Inquiring and designing, C Processing and evaluating, D Reflecting on the impacts of science.

In this course we practise it as three tasks — Task 1 (A, 25 marks), Task 2 (one investigation, B 25 + C 25) and Task 3 (a real-world issue, D 25). The real paper mixes a little more: one numbered question may carry A and C marks, and a data question may sit next to a design question.

The shape is stable. The five Physics papers from 2021 to 2023 each have eight questions. They open with short knowledge items, put one long design question in the middle, and end with a long discuss and evaluate question.

SessionQuestionsThe design questionThe longest discuss-and-evaluate question
May 20218Q5b, surface area of a parachute and time to fall [13]Q8, drones in surveillance [14]
November 20218Q6b, number of bulbs in series and current [15]Q8b, Malta’s energy options [12]
November 20228Q5, voltage and the time for a motor to lift a mass [14]Q8b, ultrasound and X-ray imaging [16]
May 20238Q5b, temperature and the circumference of a balloon [14]Q7d, mobile-phone location tracking [13]
November 20238Q6a, sponge thickness and table-tennis ball bounce [14]Q8, upgrading houses to passive standards [13]

Two things follow. First, 27–30 marks of every paper sit in just two questions — the design and the long discussion. Second, those long questions come with bullet points, and the markscheme follows the bullets. The other six questions are mostly data and knowledge items of 7–20 marks, each built round one context: Marconi’s radio, horses on a hill, Galileo’s ramp, a kidney stone.

Calculator Formula sheet Symbols Graph Ruler Time 96:40 Question 3b [3] Construct a circuit to measure the current through the lamp. celllamp Drag a symbol onto the circuit: V resistorvoltmeter ammeter A

Why does the order matter to you? Because marks are not spread evenly across the time. The first questions are dense with 1- and 2-mark items that take a minute each; later questions hold a design worth 13–15 marks and a discussion worth 12–16 marks, each needing 15–20 minutes of typing. Students who spend the first hour polishing 1-mark answers are the students who arrive at the last question with ten minutes left.
True or false?

“Every question on the real Physics paper tests only one criterion, so the paper has exactly three sections.”

Reveal answer

False. The questions are numbered continuously, one to eight, and the criteria are spread across them. November 2022 Q6, for example, mixed a knowledge calculation (the gain in gravitational potential energy) with organising raw data into a table (Criterion C).

What is stable is the pattern: short knowledge items first, investigations in the middle, discussion last.

1.2 The on-screen tools and item types: what each asks of you

Every item is answered on screen. The toolbar gives you a calculator, a formula sheet, a symbol palette and, where an item needs them, a table tool, a graph plotter, a drawing canvas and a measuring tool. Simulations and videos are the stimulus for many items.

Each item type has its own way of losing marks. The table lists the types in the Physics and Integrated Sciences papers from 2021 to 2023, with a real item and the trap.

Item type and toolWhat you doReal itemThe trap
Select (options or drop-down)Click one option, or pick words inside a sentenceMay 2021 Q1b: the bending of radio waves round obstacles — diffractionChoosing the near-miss (refraction); leaving a drop-down on “?”
Drag-and-drop labelsDrag words or particles into boxes on a diagram or equationMay 2023 Q3d: ⁴₂α and ⁰₋₁β into two decay equationsNot checking that mass and atomic numbers balance on both sides
Numeric box with the calculatorType a value; working can go in the boxMay 2023 Q1e: minimum power of a horse, in kW [3]Answer in W when kW was asked; no working, so no ECF
Table tool (“Organize”)Build a results table from a notebook of raw dataNovember 2021 Q4a: voltage and current for component X [6]Units in every cell; rows not in order; decimals inconsistent; mA not converted
Graph plotterSet scales, drag points, draw a line of best fitMay 2021 Integrated Sciences Q4d: current against voltage [5]Uneven scale; points using less than half the grid; line forced through an anomaly
Drawing canvasDrag circuit symbols and wires into placeNovember 2022 Q4d: ammeter in series, voltmeter across the motor [3]Voltmeter in series; extra components added
Measuring tool or simulationMove a screen, ruler or slider and read a scaleMay 2021 Q6a: image distance from a sharp image on a lens bench [3]Reading the scale position instead of the distance from the lens
Open response boxType the answer; long questions show bullets above a large boxNovember 2022 Q8b: ultrasound and X-rays [16]A bullet ignored; no concluding appraisal

The formula sheet matters more in Physics than in any other science paper. Items say “use the formula sheet” (May 2023 Q1e, Q2d, Q4d; November 2023 Q3c), so you do not need to memorise every equation. You do need to recognise which one fits, rearrange it and convert units first. The sheet will not tell you that 750 nm is 7.50 × 10⁻⁷ m.

The Physics May 2023 report praised the “increased number of students using the online tools to present their working”. Working typed into the box is what lets an examiner award method marks and ECF.

Two screen habits that cost marks every session. First, superscripts: the May 2021 markscheme for Q3b gave a separate mark for the unit m s⁻², and “^2 was not accepted”. Use the symbol palette for ⁻¹, ², °, Ω and μ. Second, a blank is always zero: a considered choice in a drop-down or a drag-and-drop box scores at least sometimes.
EXAMPLE — a table-cell calculation (May 2021 Physics style)

A ball rolls from rest down a ramp. The table has columns distance / m, time / s and (time)² / ______. The rows above show 1.04, 1.93, 3.06 and 3.92. For the last row the time is 2.19 s. Label the missing unit and calculate the missing value.

(time)² = t × t

(time)² = 2.19 s × 2.19 s

(time)² = 4.7961 s²

(time)² = 4.80 s² (2 decimal places, matching the column)

The markscheme gave one mark for the unit s² (with a real superscript), one for the calculation and one for 4.80 to two decimal places. Typing 4.7961 showed the arithmetic but not the judgement.

Apply

A current column reads 0.20, 0.41, 0.60, 0.81 and 1.01 A. The notebook gives the current at 3.0 V as 601 mA. What value do you type into the table?

Reveal answer

601 mA = 601 ÷ 1000 A

601 mA = 0.601 A

Typed value: 0.60 (2 decimal places, like the rest of the column; unit in the heading only)

This is November 2021 Q4a: the markscheme gave marks for units in the headers only, for data in order and for every current to 2 d.p.

EXAMPLE — the measuring tool in an unfamiliar set-up (May 2021 Physics style)

A candle is fixed at the 0 cm mark of a metre rule and a convex lens at the 30.0 cm mark. You slide the screen until the image is sharp. The magnifier on the screen shows the scale reading 42.8 cm. Determine the image distance di, the distance from the lens to the screen.

di = screen reading − lens reading

di = 42.8 cm − 30.0 cm

di = 12.8 cm

The markscheme awarded the reading (42.8 ± 0.1), the subtraction (with ECF) and the unit cm, which was “awarded independently if seen anywhere”. The trap is typing the reading, 42.8, as if it were the distance.

0102030405060 cm candle lens at 30.0 cm d(i) = 12.8 cm screen: sharp image at 42.8 cm

Spot the errors

A student builds a table with the table tool. Headings: “Voltage” and “Current”. Cells: 1.0 V, 2.0 V, 4.0 V, 3.0 V, 5.0 V in the first column; 0.2 A, 0.41 A, 0.81 A, 601 mA, 1.01 A in the second. Find four errors.

Reveal answer

Units are in every cell instead of in the headings only: write “Voltage / V” and “Current / A”. The rows are not in order: 4.0 V comes before 3.0 V.

The decimals are inconsistent: 0.2 should be 0.20. And 601 mA has not been converted: it is 0.60 A. These are the four marking points of November 2021 Q4a; the November 2025 report says table questions cause problems “as it always seems to”.

The corrected table:

Voltage / VCurrent / A
1.00.20
2.00.41
3.00.60
4.00.81
5.01.01

1.3 Timing: 120 minutes, 100 marks, and where the minutes go

The simplest rule is about 1.2 minutes per mark. A 2-mark item deserves under three minutes; a 14-mark design deserves about 17 minutes; a 16-mark discussion about 19. Applied to the course’s three-task shape, it gives this plan.

BlockMarksMinutesWhat you are doing
First read—5Scroll the whole paper; find the design question and the long discussion; note their marks
Task 1 — Criterion A2525Short items; formula sheet open; never more than 3 minutes on a 1–2 mark item
Task 2 — Criteria B and C5055Design (about 17 minutes), then tables, graphs and gradients
Task 3 — Criterion D2530Sources first (5 minutes), then the long answer bullet by bullet
Check—5Blanks, units, superscripts, precision, the concluding appraisal

Task 1 · A25 min Task 2 · B and C55 min Task 3 · D30 min 053085115 ≈ 1.2 minutes per mark Read: 5 minCheck: 5 min minutes from the start 120 minutes, spent in the order the marks sit

Physics students have usually found the time fair. The Physics May 2026 report noted “very few blank responses”. The risk is not running out of paper — it is spending twelve minutes on a 3-mark calculation you cannot crack. Write what you have, show your working for method marks, note the question number and move on.

What if?

At 75 minutes a student has finished everything up to the design question. Remaining: the design [14], a data question [10] and a discuss-and-evaluate question [13]. How should the last 45 minutes be split?

Reveal answer

37 marks remain in 45 minutes, about 1.2 minutes per mark: design about 16 minutes, data about 12, discussion about 15, leaving 2 minutes to check.

Long questions are marked point by point against their bullets, so a structured partial answer to each scores far more than a perfect answer to one and nothing on another. The concluding appraisal alone is often worth 2 marks, so write it even if the middle of the discussion is thinner than you wanted.

1.4 Command terms: the verb decides the depth

Every question starts with a command term. It tells you how deep the marks go. The Physics May 2025 report flagged “the use of the command term ‘evaluate’ in addition to ‘discuss'” for extended questions. Every Biology report since 2023 has made the same point about command terms in general.

Command termWhat it demandsFrom a real Physics paper
Select / IdentifyPick or name the one right thing from what is givenMay 2021 Q1b: the phenomenon in the animation — diffraction
StateA name, value or short fact; no explanationNovember 2023 Q1b: an object in the Solar System not made by humans — a comet
LabelPlace names or values on a diagramNovember 2023 Q3a: light, 5 J and thermal, 95 J on a Sankey diagram
OutlineA brief account: two linked points for two marksMay 2021 Q3f: why reducing car fuel is globally significant — CO₂, then climate change
DescribeWhat happens, or what the data show, in detailMay 2023 Q4e: as pressure increases volume decreases, inversely
ExplainReasons: a chain from cause to effect through the mechanismMay 2023 Q2b: why red light is at the top of the spectrum [3]
SuggestA plausible idea in an unfamiliar contextMay 2021 Q4f: why a water clock made sharing results hard
CalculateA numerical answer with working and unitMay 2023 Q1e: minimum power of horse B, in kW [3]
DetermineObtain one value, often from a graphNovember 2022 Q1c: the half-life of barium-141, 18.5 min
FormulateA testable hypothesis or research questionMay 2021 Q5a: If … then … because, with forces and particle theory [3]
JustifyValid reasons or evidence for a choiceNovember 2022 Q2e: which student is right about evaporation
Compare (and contrast)Similarities and differences, each in a sentence naming bothNovember 2022 Q2b: evaporation and boiling [2]
Organize / PresentBuild a correct table from raw dataNovember 2023 Q5c: coefficient of restitution table [6]
Construct / DrawA circuit, line of best fit or diagram with standard symbolsNovember 2021 Q6a: two bulbs and an ammeter in series [3]
DesignA plan: variables, hypothesis, equipment, method, sufficient data, safetyNovember 2021 Q6b [15]
Evaluate / DiscussEvaluate: weigh strengths and limitations. Discuss: arguments on both sides. Both end in a supported judgementNovember 2023 Q4h: evaluate a prediction [3]; November 2022 Q8b [16]

Stateone fact or value Outlinetwo linked points Describewhat happens,with values Explaincause → force,particles, energy Discuss andevaluateboth sides +a judgement

Question: “Explain why red light is at the top of the spectrum.” Answer: “Because red is refracted differently.” That names the effect without the mechanism. Say: “Red light has the longest wavelength (lowest frequency) of the visible colours [1]; it is slowed down least by the glass, so it has the lowest refractive index [1]; so it is refracted (bent) the least and ends up at the top [1].” That is the May 2023 Q2b markscheme in order.
Explain

One question says “Outline how passive houses stay warm while needing less heat” [2]. Another says “Use kinetic theory to explain why the balloon expands when the gas is heated” [3]. Write a one-line plan for each.

Reveal answer

Outline [2]: good insulation reduces heat loss [1], so less extra heat is needed to keep the inside at a comfortable temperature (November 2023 Q7a) [1].

Explain [3]: the particles gain kinetic energy and move faster [1] → they hit the walls more often and with more force [1] → the pressure rises, so the elastic wall is pushed out and the balloon expands [1] (November 2021 Q1c). Three marks means three linked steps, reaching the particles.

Apply

“Compare the efficiency of an LED with that of a filament bulb” [3]. The filament bulb gives 5 J of light per 100 J in; the LED gives 0.02 W of light from 0.05 W in. Write the answer.

Reveal answer

Filament efficiency = 5 J ÷ 100 J × 100

Filament efficiency = 5 % [1]

LED efficiency = 0.02 W ÷ 0.05 W × 100

LED efficiency = 40 % [1]

So the LED is eight times as efficient as the filament bulb (40 % compared with 5 %) [1]. The November 2023 Q3d markscheme gave the comparison mark only when both efficiencies had been found.

1.5 Reading the stem, the bullets and the stimulus

Before you type anything, find four things. The command term. The marks — each mark is usually one point. The object — “the height of the first bounce”, not “the ball”. Any constraint: “give your answer in kW”, “to two significant figures”, “in scientific notation”, “include a unit”, “use the formula sheet”, “refer to particle theory”.

In Physics the constraints carry marks of their own. May 2021 Q1c gave a separate mark for writing the time in standard form; May 2023 Q7a gave separate marks for two significant figures and for the unit hertz. Underline them as you read.

Long questions add bullets; the markscheme follows them. Stimulus — a video transcript, a simulation, a table — is your raw material, not your answer: “This was information that was given in the question and as such was not worthy of credit” (Physics May 2024).

Stem phraseWhat it forces
“Give your answer to 2 significant figures”Exactly two: 7.3, not 7.27 or 7
“In scientific notation”a × 10ⁿ with 1 ≤ a < 10: 2 × 10⁻⁵ s, not 0.00002 s
“Include a unit”A mark that is often awarded independently of the number
“Refer to particle theory / forces / energy”The mechanism: collisions, resultant force, named energy stores
“Use your answer to part (e)”ECF: your earlier value, even if wrong, can carry the method mark
“From the perspective of a country”Argue from that seat only (May 2023: an individual’s view scored nothing)
Spot the errors

“Calculate the time taken for the radio message to travel 6 km. The speed of radio waves is 3.0 × 10⁸ m s⁻¹. Give your answer in scientific notation.” A student types: “t = 6 ÷ 300 000 000 = 0.00000002”. What is wrong?

Reveal answer

The distance was not converted: 6 km is 6000 m. The answer is not in scientific notation, and there is no unit.

t = d ÷ v

t = 6000 m ÷ (3.0 × 10⁸ m s⁻¹)

t = 2 × 10⁻⁵ s

May 2021 Q1c gave a mark for the conversion, one for the value and one for standard form — which was “awarded even if the value is wrong but written in standard form”.

1.6 How the markscheme thinks: ECF, WTTE, ORA and independent marks

ECF — “error carried forward”: a later step that uses your wrong earlier value correctly still earns its marks. WTTE — “words to that effect”. ORA — “or reverse argument”: the same idea argued the other way round.

Independent marks are common in Physics: the unit, the significant figures and the standard form are often separate marks, so a correct unit on a wrong number still scores. Correct answer alone: many calculations say “award all marks for the correct final answer” — but only if it is right, so show working anyway.

Gated marks need an earlier mark first: in May 2023 Q6e, “the hypothesis is not valid” scored only after the trend and the proportionality points. Do not accept lists near-misses: “unnamed greenhouse gases” for CO₂ (May 2021 Q3f); “deformation of the ball” as the energy lost (November 2023 Q4d).

True or false?

“If my number is wrong, writing the unit is pointless.”

Reveal answer

False. The unit mark is frequently awarded independently. May 2023 Q7a gave one mark for the frequency range, one for two significant figures and a separate mark for Hz or s⁻¹. In May 2026 Q1b, the report notes that students without a unit “got only 1 mark out of the 2”.

Stretch

A horse of weight 5100 N climbs a hill 12 m high in 5.50 s. A student calculates the work done as 5100 × 1.2 = 6120 J (a slip with the height), then the power as 6120 ÷ 5.50 = 1112.7 W, and writes “1.11 kW”. The markscheme gives 1 mark for work, 1 for power and 1 for the answer in kW, with ECF. How many marks, and what is the correct answer?

Reveal answer

The work mark is lost. With ECF the power and the kW conversion are marked on 6120 J, and both are correct for that value, so 2 of 3.

W = F × d

W = 5100 N × 12 m

W = 61 200 J

P = W ÷ t

P = 61 200 J ÷ 5.50 s

P = 11 127 W

P = 11.1 kW (3 significant figures)

This is May 2023 Q1e, where “ECF applies” was written into the markscheme.

Try it — work the lab as an on-screen data question

The pendulum lab practises the Criterion C skills the Physics May 2026 report named: “demonstrating direct proportionality, linearising data, determining appropriate gradient units and interpreting the physical meaning of gradients”. A bob hangs on a string of length L; you time ten swings with a stopwatch.

1

Research question and hypothesis. “How does the length of the string, from 0.20 m to 1.00 m, affect the period of a simple pendulum with a 100 g bob released from 15°?” If the length increases, then the period will increase, but not in proportion, because for small swings T = 2π√(L ÷ g): the bob has a longer arc, while gravity sets its acceleration. So T² should be directly proportional to L.
2

Variables. IV: string length in m, set and measured with a metre rule to the centre of the bob — 0.20, 0.40, 0.60, 0.80 and 1.00 m. DV: the time for 10 swings, read on a stopwatch. Controls with values: bob mass 100 g; release angle 15°, checked with a protractor; the same rigid clamp.
3

Collect. Three timings of 10 swings at each length. Record length / m and time for 10 swings / s in the headings, all times to 2 decimal places.
4

Process like the table tool. Mean time for 10 swings; period T = mean ÷ 10; then T². Plot T² / s² (vertical) against L / m (horizontal) with even scales. The model gives a straight line through the origin with gradient close to 4.02 s² m⁻¹.
5

Interpret the gradient. The gradient is 4π² ÷ g, so g = 4π² ÷ gradient. Its unit comes from the axes: s² ÷ m = s² m⁻¹. Then switch the bob mass and the angle: the time does not change beyond random scatter, which is a control you have now tested.
Analyse

A student’s mean times for 10 swings are 8.97 s (0.20 m), 12.69 s (0.40 m), 15.54 s (0.60 m), 17.94 s (0.80 m) and 20.06 s (1.00 m). Calculate T² for 0.40 m and 1.00 m, the gradient, and g [4].

Reveal answer

T(0.40 m) = 12.69 s ÷ 10 = 1.269 s

T² = 1.269² = 1.610 s²

T(1.00 m) = 20.06 s ÷ 10 = 2.006 s

T² = 2.006² = 4.024 s² [1]

gradient = (4.024 − 1.610) s² ÷ (1.00 − 0.40) m

gradient = 2.414 s² ÷ 0.60 m

gradient = 4.02 s² m⁻¹ [1 value, 1 unit]

g = 4π² ÷ 4.02 s² m⁻¹

g = 9.82 m s⁻² [1]

Common mistakes to avoid

  • Leaving units off, or typing them with letters — “m/s^2” instead of m s⁻², “C°” instead of °C; the unit is often a separate mark.
  • Substituting before converting — ms, km, nm, MJ and days go to base units first.
  • Ignoring the stated precision — “20 instead of 20.0” (Physics May 2025) and “to 2 significant figures” lose marks on correct physics.
  • Treating the paper as evenly timed — the design and the long discussion hold 27–30 marks; protect their minutes.
  • Answering the topic, not the command term — a description where “explain” asked for the mechanism.
  • Copying the stimulus back — “not worthy of credit” (Physics May 2024).
  • Hiding the working — without it there is no ECF and no method mark.
  • Tables with units in every cell or rows out of order — the Organize item’s four easy marks.

Study smart: how this is examined

Learn by heartThe four criteria and their roughly 25 marks each; 120 minutes; about 1.2 minutes per mark; the meaning of each command term in Section 1.4; SI units and the prefixes k, M, G, m, μ, n; the markscheme words ECF, WTTE, ORA and “do not accept”; that the unit mark is often independent.
Practise until automaticFinding the command term, marks, object and constraint of any question in ten seconds; converting prefixes; standard form; rounding to stated significant figures; typing m s⁻², Ω, °C and μ from a symbol palette; building a table with units in the headings only.
Examiner traps“The time in milliseconds was commonly not converted to seconds” (Physics May 2025); “incorrect numerical precision (e.g., 20 instead of 20.0)” (May 2025); “a sizeable number of students did not give their answer an appropriate unit” (May 2026); data tables causing problems “as it always seems to” (November 2025).
Command terms you will meetSelect and identify: one right thing. State: a word or value. Outline: two linked points. Explain: the mechanism. Calculate: working, answer, unit. Determine: one value, often from a graph. Organize: a correct table. Evaluate and discuss: both sides and a judgement.
From a real paper: May 2021 Physics, Q4e Calculate [3]: a table of distance and time for a ball rolling down a ramp had an empty (time)² cell and no unit in that column’s heading; the markscheme wanted s² with a true superscript, the value 4.7961 and 4.80 to two decimal places to match the column. May 2023 Physics, Q1e Calculate [3]: the minimum power for a 5100 N horse to climb 12 m in 5.50 s, given in kW, with ECF written into the scheme. Try them in the MYP Sciences e-Assessment Practice course.

Study routine. Today: copy the command-term table from memory, then check it. In two days: take five calculation questions from your Unit 1–10 exams and, for each, write only the conversions, the equation and the precision required.

In a week: sit one Physics past-paper question in the practice course with a timer set at 1.2 minutes per mark, and note every item where you lost a unit or a significant figure.

How we found out — why physics agrees on units

In May 2021 the Physics paper asked why Galileo’s water clock made it hard to share his results. The answer — nobody else had an identical clock — is the reason the International System of Units exists. For most of history every town had its own foot, its own pound and its own hour.

In the 1790s revolutionary France defined the metre as one ten-millionth of the distance from the North Pole to the Equator through Paris, and surveyors Jean-Baptiste Delambre and Pierre Méchain spent seven years measuring it. In 1875 seventeen nations signed the Metre Convention, and in 1889 platinum–iridium prototypes of the metre and kilogram were kept near Paris.

In 1960 the system was named the Système international d’unités — SI. The last physical artefact went on 20 May 2019, when the kilogram was redefined by fixing the value of the Planck constant. Every SI unit is now defined by constants of nature that any laboratory can reach.

That is why the markscheme insists on the unit. A number without one cannot be checked, compared or used — exactly Galileo’s problem with his water clock.

Explain

Explain why defining the kilogram by a constant of nature is better than defining it by one metal cylinder kept in a vault.

Reveal answer

A single object can change — gain dirt, lose atoms when cleaned — and comparisons with it drifted by tens of micrograms over a century. It can only be reached by visiting it.

A constant of nature is the same everywhere and for ever, so any well-equipped laboratory can realise the kilogram independently and results agree without anyone travelling to Paris.

Where it is used now

  • Engineering drawings. Engineers building a solar farm in Botswana or a bridge anywhere in the world write every quantity with a unit and a tolerance; a missing unit is a rejected drawing.
  • Medicine. Radiotherapy doses are given in grays and infusion rates in mL h⁻¹; a prefix error of 1000 is the kind of mistake hospitals build double-checks against.
  • Aviation. In 1983 an Air Canada jet ran out of fuel in flight after a fuel load was calculated in pounds instead of kilograms; the crew glided it to a safe landing at Gimli, Manitoba.
  • Digital testing. Driving-theory tests, university entrance tests and professional licences are increasingly on screen, with the same select, drag-and-drop and typed-response items.

Science now — and the scientist you need to be

What is happening in 2026

MYP eAssessment has been on screen since its first examinations in May 2016. The Physics paper is now a mature format: simulations with sliders, video with transcripts, a formula sheet, a graph plotter and a drawing canvas for circuits.

The IB is revising the MYP (“Enhancing the MYP”), with the first new-style eAssessment expected in May 2030; the physics and the skills you are practising carry forward.

Around you, physics has moved on screen too. Data are logged by sensors, fitted in spreadsheets and plotted by software; AI assistants can explain a topic, quiz you and check a calculation. Recall is cheap. What the Physics reports keep asking for is judgement — the right equation, the right units, the right precision and a conclusion that weighs the evidence.

The mindshift

Not thisIf I know the physics, the marks follow.
But thisMarks follow the command term, the units, the precision and the bullets. Knowledge is necessary, not sufficient.
Not thisThe formula sheet means I do not need to practise equations.
But thisThe sheet gives the equation; you must choose it, convert, rearrange and round.
Not thisThe on-screen tools are a nuisance.
But thisThe tools are part of the test; practise them until they are invisible.

What you need to be able to do

Read any question for its command term, marks, object and constraint; plan 120 minutes; convert and type values with the right precision and symbols; and mark your own work with the markscheme’s conventions.

Apply it this week. Ask an AI assistant to write six Physics questions on one unit, each with a different command term (state, outline, describe, explain, calculate, evaluate) and marks in brackets. Answer each yourself, then check each answer against Section 1.4. Note any question where the assistant’s own model answer did not match its command term.

See an example

For Unit 4 Thermal physics an assistant wrote “Explain why a pan handle is made of plastic [3]”. Its model answer — “plastic is an insulator” — is a statement worth one mark.

A full answer adds the mechanism: plastic has no free electrons and its molecules pass on vibrations slowly, so it is a poor conductor [1]; little thermal energy is conducted from the hot base to the hand [1]; so the handle stays cool enough to hold without a burn [1].

Key terms

eAssessmentThe MYP on-screen examination: 2 hours, 100 marks, Criteria A–D.
Command termThe verb at the start of a question that sets the depth and type of answer.
Formula sheetThe on-screen list of equations; you choose, rearrange and apply the right one.
Table toolThe on-screen grid used for “Organize” and “Present” items.
Graph plotterThe tool for setting scales, plotting points and drawing a line of best fit.
Drawing canvasThe tool for building circuit diagrams from standard symbols.
Measuring toolAn on-screen ruler, screen or slider read against a scale.
ECFError carried forward: a later step using a wrong earlier value can still score.
WTTE / ORAWords to that effect / or reverse argument: equivalent answers are credited.
Independent markA mark (often the unit or significant figures) awarded whether or not the number is right.
LinearisingPlotting a changed quantity (such as T² or 1 ÷ d²) so that a curved relationship becomes a straight line.

Think like a scientist

Criterion A A village borehole in the Kgalagadi uses a solar-powered pump. On a sunny day it lifts water from 40 m below the surface into a storage tank. The engineer’s data: in one hour the pump lifts 500 kg of water; the solar panels deliver 150 W of electrical power to the pump.

(a) State the energy store of the water that increases as it is lifted. [1]

(b) Outline the energy transfers from the Sun to the water in the tank. [2]

(c) Calculate the gain in gravitational potential energy of the water in one hour. Use g = 9.8 N kg⁻¹. [2]

(d) Calculate the efficiency of the pump. Give your answer to 2 significant figures. [3]

(e) Explain why the pump lifts less water on a cloudy day. [2]

(f) Suggest one reason why the tank is placed higher than the houses it supplies. [1]

Model answer

(a) Gravitational potential energy [1]. State = one term.

(b) Light (radiant) energy from the Sun is transferred to electrical energy in the solar panels [1]; the motor transfers electrical energy to kinetic energy of the pump and then to gravitational potential energy of the raised water, with some thermal energy wasted [1]. Two energy forms are needed for each transfer (Physics May 2026).

(c) ΔEp = mgΔh

ΔEp = 500 kg × 9.8 N kg⁻¹ × 40 m

ΔEp = 196 000 J (1.96 × 10⁵ J) [2]

(d) Energy in = P × t

Energy in = 150 W × 3600 s

Energy in = 540 000 J [1]

Efficiency = useful energy out ÷ total energy in × 100

Efficiency = 196 000 J ÷ 540 000 J × 100

Efficiency = 36.3 %, which is 36 % to 2 s.f. [1 calculation, 1 significant figures]

(e) Less light energy reaches the panels each second, so they deliver less electrical power [1]; the pump then does less work each second, so less mass of water gains the same gravitational potential energy in an hour [1].

(f) Water flows from the tank to the houses under gravity, so no pump is needed at night or when it is cloudy (the stored GPE provides the pressure) [1].

Probe deeper — exam-style questions

Attempt every question before opening the answer. Marks in brackets show what a full answer is worth.

[2]1

State the length of the MYP Physics eAssessment and the approximate number of marks for each criterion.

Reveal answer

120 minutes (2 hours) [1]; about 25 marks for each of Criteria A, B, C and D, 100 in total [1].

[2]2

Red light has a wavelength of 750 nm and travels at 3.00 × 10⁸ m s⁻¹. Calculate its frequency, in scientific notation.

Reveal answer

750 nm = 7.50 × 10⁻⁷ m

f = v ÷ λ

f = 3.00 × 10⁸ m s⁻¹ ÷ 7.50 × 10⁻⁷ m

f = 4.00 × 10¹⁴ Hz [2]

This is May 2023 Q2d; the May 2025 report found many students “failed to convert 550 nm into metres” in the same kind of item.

[2]3

Distinguish between “describe” and “explain” using the graph of pressure against volume for a fixed mass of gas at constant temperature.

Reveal answer

Describe: as the pressure increases, the volume decreases; doubling the pressure halves the volume (inverse proportion) [1].

Explain: in a smaller volume the particles hit each square metre of wall more often, so the force per unit area — the pressure — is greater [1].

[3]4

A design question worth 14 marks has six bullets. State how long to spend, how to lay out the answer, and one thing to check before moving on.

Reveal answer

About 17 minutes (1.2 minutes per mark) [1]. Answer under the bullets in order, as separate sections, because the markscheme follows them [1]. Check: five values of the IV and three repeats with a mean are stated; every control has a value; the DV is read from a named instrument [1].

[2]5

Explain what “ECF” means and why it is a reason to show working in a multi-step calculation.

Reveal answer

Error carried forward: when an earlier value is wrong, a later step that uses it correctly can still earn its marks [1]. The examiner can only see a correct method if the working is shown; a bare wrong number scores nothing [1].

[2]6

A 0.050 kg mass is lifted 95.0 cm. A student calculates 0.050 × 9.81 × 95.0 = 46.6 J. The markscheme gave 1 of 2 marks for this. Explain why, and give the correct value.

Reveal answer

The equation was right (1 mark) but the height was not converted to metres, so the answer is 100 times too big [1].

ΔEp = mgΔh

ΔEp = 0.050 kg × 9.81 N kg⁻¹ × 0.950 m

ΔEp = 0.466 J (November 2022 Q6a)

[4]Stretch

7. A paper’s items are worth: eleven short items totalling 24 marks, a data question of 18, a design of 14, a data question of 14, a short media question of 8, a discuss-and-evaluate question of 13, and two final items totalling 9. Build a timed plan with 5 minutes to read and 5 to check, and justify one change for a slow typist.

Reveal answer

Marks total 24 + 18 + 14 + 14 + 8 + 13 + 9 = 100; 110 minutes of working time gives 1.1 minutes per mark [1].

Short items: 24 × 1.1 ≈ 26 min

First data question: 18 × 1.1 ≈ 20 min

Design: 14 × 1.1 ≈ 15 min

Second data question: 14 × 1.1 ≈ 15 min

Media question: 8 × 1.1 ≈ 9 min

Discuss and evaluate: 13 × 1.1 ≈ 14 min

Final items: 9 × 1.1 ≈ 10 min [2 for a complete plan of about 110 minutes]

A slow typist should answer the short items tersely (state = a word or value) and move those minutes to the design and the discussion, which are marked point by point and need the most typing [1].

[4]Stretch

8. The grade 7 boundary in Physics was 82 marks in May 2023, 76 in May 2025 and 75 in May 2026. A student scores 22 on Criterion A, 19 on B, 18 on C and 13 on D. Calculate the total and the marks missing for a 7 in each session, and explain which criterion offers the cheapest marks, using the reports.

Reveal answer

Total = 22 + 19 + 18 + 13

Total = 72 marks [1]

Short of a 7 in May 2023: 82 − 72 = 10 marks

Short of a 7 in May 2025: 76 − 72 = 4 marks

Short of a 7 in May 2026: 75 − 72 = 3 marks [1]

Criterion D is the cheapest to raise: 13 of 25 is lost mostly by structure [1]. The Physics reports say missing conclusions cost “a possible 2 marks” (May 2025) and that “conclusions often summarised information rather than weighing evidence” (May 2026), so balanced points with physics support and a weighed appraisal could add 5–8 marks with no new physics [1].

Summary

  • The Physics eAssessment is 120 minutes and 100 marks, about 25 for each of Criteria A–D; papers have eight questions, with a long design question in the middle and a long discuss-and-evaluate question at the end.
  • The tools — calculator, formula sheet, symbols, table tool, graph plotter, drawing canvas and measuring tool — each have a trap: missing units and superscripts, unconverted prefixes, units in every cell, uneven scales, voltmeters in series.
  • Spend about 1.2 minutes per mark; protect the 27–30 marks in the design and discussion questions.
  • The command term sets the depth: state a fact, outline two linked points, describe with values, explain the mechanism, calculate with working and unit, evaluate and discuss both sides with a judgement.
  • Markschemes use ECF, WTTE, ORA, independent unit and precision marks, gated marks and “do not accept” — show working, convert first, and write the unit every time.

Next time → Criterion A across the whole course: a topic-by-topic checklist of everything the Physics eAssessment can ask, with a retrieval question for each.