Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ b0fa825
Topic 12 — How to build and test an energy changer — the PP100's ten question types, with their exemplars
What this page is. James reads a bank as its question TYPES first (vault: A bank is reviewed as its question types first, one exemplar each). Under the Grade 4 standing brief the bank is built straight away (51 items in content/G4T12_pp100_bank.py, v3 of 2 Oct 2026 — the blind read, the guidance review and the figure review applied; the paper-spiral item cut, the items renumbered; the v2 re-read's two polish notes applied to PP-4 and PP-32); this sheet is the way in. Each type line says what the stem asks, what the four options (or the accept list) are, and prints one exemplar in full. Tags follow depth of reasoning — easy = one-step sort or recall; medium = the rule applied to a fresh case, a card matched, or the reason picked; hard = two ideas held apart, an unfair test repaired, or the rule's word produced — and rise with the atom's order: ENE4-070 carries easy and medium only; SR4-023, the capstone, is mostly hard. Every hard item carries a one-line "hard because" in the bank file.
Rulings already applied. The still-wheel option is "Nothing pushes them round." — the push that is missing is the push ROUND; a still wheel still has Earth's pull and the straw's push on it (FOR-03, the review's Essential 1). Four options on every MCQ; no option bundles a verdict with its reason; every stem is a positive question; "energy changer", "criterion" and "constraint" are chosen among sister words, never typed (RECALL_BY_MCQ); the five typed keys are lexicon words (energy · plan · design · test · same), closed questions; no multi-select; every item names ONE atom; US spelling; units as words; the verdict words are "does the job" / "does not do the job yet" (met / not met are Grade 5's); energy "comes in with" / "goes out with" a thing, never "a form of energy"; the wind HAS kinetic energy, it is not energy.
The bar list (things a generated item must never say): "the wind is energy"; "makes energy" as a key; "a form of energy"; "met" / "not met"; a two-step chain asked in one item (ENE4-071 is one-step; the one hard item that touches two steps asks for ONE of them); any device whose energy path a 9-year-old cannot see (a solar cell, a battery charging, a generator's inside); "lift" in any figurative sense. Claim-makers and characters are only Eden, Edgar and Eliza (the topic's row in grade4/NAMES_POOL.md).
The ten types
| Type | Items | Atom | Tags | Form | The stem asks… | The options / the accept | Exemplar scene |
|---|---|---|---|---|---|---|---|
| 1 | 7 | ENE4-070 | easy | MCQ, fixed set | a wheel of blades or paddles spins, or stands still: what pushes the blades round | the moving air / the moving water / the sunlight / Nothing pushes them round. | a propeller hat on a windy hilltop; a paddle wheel under a waterfall; a weather vane's propeller with no wind; a toy sailboat's propeller on a calm pond; a lawn sprinkler's stream on a garden wheel; a windmill beside a limp windsock in a closed gym; a wheel blown through a straw |
| 2 | 5 | ENE4-070 | easy, medium | MCQ | which of four can push a wheel round; a kite-tail wheel; what the wind is; which thing has kinetic energy; why a propeller stops indoors | four things, or four one-sentence answers | a river past its stones, a bridge and a wheel; the wind as "moving air that has kinetic energy" |
| 3 | 3 | ENE4-071 | easy | MCQ, fixed set IN4 | a device works: what does the energy come in with | the moving air / the moving water / electricity / a moving hand | a wind-up toy car; a plugged-in kettle; rain off a roof onto a toy wheel |
| 4 | 3 | ENE4-071 | easy | MCQ, fixed set OUT4 | a device works, and the stem names what comes OUT of it: what does the energy go out with | the turning wheel / the light / the sound / the moving air | an electric piano; a traffic light; a leaf blower ("air blows out of it") |
| 5 | 6 | ENE4-071 | medium | MCQ | where the energy a device gives out came from; which card (in with X, out with Y) matches the device; why an unplugged fan stops | four one-sentence answers, or four cards | a doorbell; a rubber-band toy boat; a sawmill wheel and its saw; an electric heater |
| 6 | 1 | ENE4-071 | medium | MCQ keyed on the term | a device takes in energy with one thing and gives it out with another: what is it called | an energy maker / an energy carrier / an energy changer / an energy giver | (definition stem) |
| 7 | 4 | ENE4-072 | easy (1 medium) | MCQ | which step comes first for a build (writing down the criterion and the constraint); a board line: criterion or constraint; why the plan is checked against the board before building | write down the criterion and the constraint / three build steps; a criterion / a constraint / a step / a test; four reasons | a marble track's first step; a wheel to lift a toy car and its board's two lines |
| 8 | 9 | ENE4-072 | medium → hard | MCQ; 2 typed | what hands energy into the reel first (v3: "first", so the pencil axle inside the reel is a tempting-wrong, not a second key); which part hands energy to the flag; the missing step; what happens when the axle is glued (the spool is fixed to it); which build step comes NEXT, after the plan is written; the SECOND change as a card; the rule's words (typed: energy; plan) | parts of the build; four short cards "in with X, out with Y"; accept: energy forms; plan forms ("idea" refused) | a hand-cranked reel: a cardboard spool on a pencil axle, turned by a handle, winding a ribbon that raises a small paper flag (fresh: no lesson, quiz or practice scene has a reel) |
| 9 | 10 | SR4-023 | easy → hard | MCQ; one drawn table | the one thing that changes; what stays the same; does the design do the job; besides the design, how many OTHER things changed; what tells the class; which designs do the job (boundary case); the likely unfair change; the fair re-test | design / height / …; It does the job. / It does not do the job yet. / Nobody can tell. / It does half the job.; Eden's / Edgar's / both / neither; four conditions | paper spinners against "3 seconds or more"; cup towers holding a book; a kite flown on a windier day; a toy car let go from higher up the ramp |
| 10 | 3 | SR4-023 | hard | typed text | finish the rule: the missing word | design · test · same (with articles and child forms) | "the same fair test for every ___"; "only the ___ tells"; "stays the ___" |
Hard because — type 8 (second change): two one-step changes are held apart and the second is picked as a card; (typed energy, typed plan): the rule's word is produced. Type 9 (three spinners): three results are read against the criterion, with the boundary case (exactly 3 seconds counts as 3 or more); (the kite): the unfair change is inferred from the verdict, with true-but-harmless facts as distractors; (the re-test): the unfair test is repaired by naming the one thing that must return to the shared value. Type 10: the rule's deciding word is produced against the pull of "how it looks".
One exemplar per type, in full
Type 1 (easy, ENE4-070). On a morning with no wind, Eden looks up at the small propeller on a weather vane. What pushes its blades round? — the moving air / the moving water / the sunlight / Nothing pushes them round. Why: With no wind, the air is still. Still air does not push the blades round, so the wheel stays still. So nothing pushes the blades round. (nearest lesson-side instance: L01-q8, the wind turbine on a calm day — a different object, no card)
Type 2 (medium, ENE4-070). The wind pushes a wheel of blades round. What is the wind? — energy itself / moving air / still air / a kind of light. Why: The wind is moving air. A moving thing has kinetic energy, so moving air has kinetic energy. The wind has energy, but the wind is not energy itself. (nearest: L01-q11, Eden's claim "the wind is energy" — there a bare yes / no; here the positive description is picked)
Type 3 (easy, ENE4-071). Edgar winds up a toy car with his hand, lets go, and the car drives off. What does the energy come in with? — the moving air / the moving water / electricity / a moving hand. Why: Edgar's hand turns the key to wind the car up. His moving hand hands energy to the car. So the energy comes in with a moving hand. (nearest: L02-q5, the hand-crank flashlight)
Type 4 (easy, ENE4-071). A leaf blower is plugged in, and it blows leaves across the yard. What does the energy go out with? — the turning wheel / the light / the sound / the moving air. Why: The leaf blower blows air across the yard. That moving air is what the blower gives out. So the energy goes out with the moving air. (nearest: L02-q6, the desk fan)
Type 5 (medium, ENE4-071). At an old sawmill, a river turns a big wheel, and the wheel moves a saw that cuts logs. Which card matches the sawmill wheel? — in with the moving air, out with the moving saw / in with the moving saw, out with the moving water / in with the moving water, out with the light / in with the moving water, out with the moving saw. Why: The river is moving water, and it pushes the wheel round, so energy comes in with the moving water. The wheel moves the saw, so energy goes out with the moving saw. (nearest: L02-q9, the windmill's grinding stone wheel — moving air there, moving water here, a saw not a wheel, and both ends asked at once)
Type 6 (medium, ENE4-071). A device takes in energy with one thing and gives it out with another thing. What is such a device called? — an energy maker / an energy carrier / an energy changer / an energy giver. Why: A device that takes in energy with one thing and gives it out with another thing is called an energy changer. It makes no energy, so it is not a maker. A carrier is the thing that carries energy, such as electricity or light.
Type 7 (easy, ENE4-072). A class builds wheels to lift a toy car. The board says: 'The wheel must lift the toy car off the floor.' Which kind of line is this? — a step / a test / a criterion / a constraint. Why: A criterion is a job the design must do. 'Lift the toy car off the floor' says what the wheel must do. So the line is a criterion. (nearest: L03-q4, the water-wheel board's paper-clip line; v3 put two definition items ahead of the board items)
Type 8 (hard, ENE4-072). In Eden's reel, her moving hand turns the spool, and then the spool winds a ribbon that raises a flag. Which card says the second energy change? — in with a moving hand, out with the turning spool / in with the turning spool, out with the rising flag / in with the rising flag, out with a moving hand / in with the ribbon, out with a moving hand. Why: The first change is in with a moving hand, out with the turning spool. The second change starts where the first one ends, with the turning spool. So the second change is in with the turning spool, out with the rising flag. (nearest: L03's article, the two cards for Eliza's pinwheel lifting a cup — here a hand-cranked reel raises a flag, and the second card is picked rather than shown; the four options are short cards, not four long sentences)
Type 9 (medium, SR4-023, drawn). A class drops paper spinners from the same chair against the criterion 'take 3 seconds or more to fall', and here is the test table. Which design does the job? — Eden's / Edgar's / both / neither. Why: The criterion says 3 seconds or more. Eden's spinner took 4 seconds, and 4 seconds is more than 3 seconds. Edgar's took 2 seconds, which is less than 3 seconds. So Eden's design does the job. (figure pp_table_spinners; the verdict column is empty; nearest: L04-q4/q5 on the sail table — there one design at a time)
Type 10 (hard, SR4-023, typed). Finish the rule: only the ___ tells whether a design does the job. Type the missing word. — accept: test, the test, a test, fair test, the fair test, a fair test, testing, the testing. Why: Only the test tells whether a design does the job. How the design looks does not tell you. (nearest: L04-q11, the kites — there the same fact chosen among three)
⟂ pairs — never drawn into one PP100 form together (v2, from the blind read and the review; new numbering)
PP-17 ⟂ PP-18 (the toy-car board's two lines) · PP-1 ⟂ PP-23 (a propeller in a breeze; the propeller that stops indoors) · PP-40 ⟂ PP-46 (the spinners table; the three spinners with the boundary case) · PP-36 ⟂ PP-45 ("check each plan against the board" beside the typed word plan) · PP-42 ⟂ PP-50 ("the test" keyed beside the typed word test) · PP-20 ⟂ PP-51 ("stay the same" beside the typed word same) · PP-19, PP-38, PP-39, PP-40 ⟂ PP-49 ("design" printed beside the typed word design) · PP-49 ⟂ PP-50 (the typed design stem prints "fair test"; the typed test item). Across sections (the forms never mix them, recorded for the tracker): PP-21 states what L01-q11 asks (the wind is moving air); PR-14 ⟂ PR-15 (the kite problem's two lines; three options each, so still a choice); PR-11 and PP-42 print "the test" that PP-50 types. The typed stems describe without printing their word.
One for James — the hard-tier term-recall exemption (recorded, not a fix)
The vault's 30 Sep refinement says the hard tier recalls every coined term. Here the three terms ("energy changer", "criterion", "constraint") are recalled by MCQ at easy / medium (PP-17, PP-18, PP-30; RECALL_BY_MCQ — a 13-letter term and Topic 11's nine- and ten-letter words are never typed), and the hard tier produces the rule's plain words instead (energy · plan · design · test · same). The reviewer's recommendation, built: accept as built and record the exemption here. Scope: this topic's bank; it does not change the 30 Sep rule for topics whose coined terms are typeable.