src/lib/teaching/electromagneticInductionLessonSeeds.ts

import type { LessonSeedSourceRef, TuitionLessonSeed } from "./physicsLessonSeeds";

/**
 * Kerala SCERT Class 10 Physics - Chapter 6
 * "Electromagnetic Induction in Daily Life" (chapterId phy-p2-c6).
 *
 * Curated from the extracted chapter package and repeated question signals:
 * electromagnetic induction, magnetic flux change, generator principle, AC/DC
 * generator parts, transformers, long-distance transmission, household
 * distribution, safety fuse/MCB, earthing and ELCB. The raw definition
 * extraction is noisy, so these seeds are human-authored from source-backed
 * chapter questions, formula signals and diagrams. No PYQ claims.
 */

const EMI_SOURCE: LessonSeedSourceRef = {
  label: "Kerala SSLC Physics - Electromagnetic Induction in Daily Life (pp. 27-50)",
  sourceBook: "Kerala SCERT Physics, Standard X (2025)",
  chapterTitle: "Electromagnetic Induction in Daily Life",
  pageRange: "27-50",
  url: null,
  confidence: "source_backed",
};

const CHAPTER_ID = "phy-p2-c6";
const CHAPTER_TITLE = "Electromagnetic Induction in Daily Life";

function emiSeed(seed: Omit<TuitionLessonSeed, "chapterId" | "subject" | "chapterTitle">): TuitionLessonSeed {
  return { ...seed, chapterId: CHAPTER_ID, subject: "Physics", chapterTitle: CHAPTER_TITLE };
}

const transformerFormula = {
  formula: "Vs/Vp = Ns/Np",
  meaning: "In an ideal transformer, the voltage ratio equals the turns ratio.",
  symbols: [
    { symbol: "Vs", meaning: "secondary voltage", unit: "V" },
    { symbol: "Vp", meaning: "primary voltage", unit: "V" },
    { symbol: "Ns", meaning: "number of secondary turns", unit: "turns" },
    { symbol: "Np", meaning: "number of primary turns", unit: "turns" },
  ],
  commonUseCase: "Find secondary turns or output voltage in transformer numericals.",
  numericalPattern: "Write Vs/Vp = Ns/Np, substitute the three known values, then cross-multiply.",
};

const powerTransmissionFormula = {
  formula: "P = VI",
  meaning: "Electric power transmitted depends on voltage and current.",
  symbols: [
    { symbol: "P", meaning: "power", unit: "W" },
    { symbol: "V", meaning: "voltage", unit: "V" },
    { symbol: "I", meaning: "current", unit: "A" },
  ],
  commonUseCase: "Explain why high voltage transmission reduces current and heat loss.",
  numericalPattern: "For the same P, increasing V decreases I.",
};

const currentFormula = {
  formula: "I = P/V",
  meaning: "For a fixed transmitted power, current is inversely related to voltage.",
  symbols: [
    { symbol: "I", meaning: "current", unit: "A" },
    { symbol: "P", meaning: "power", unit: "W" },
    { symbol: "V", meaning: "voltage", unit: "V" },
  ],
  commonUseCase: "Compare current before and after step-up transmission.",
  numericalPattern: "Keep power constant, divide by the chosen voltage.",
};

const M1: TuitionLessonSeed = emiSeed({
  missionId: "M1",
  missionTitle: "Electromagnetic Induction",
  goal: "Explain how a changing magnetic field produces induced current in a conductor.",
  estimatedMinutes: 30,
  contentType: "concept",
  tags: ["electromagnetic induction", "magnetic flux", "induced current", "galvanometer", "magnet"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "What happens to a compass or magnetic needle when current flows through a nearby conductor?",
    expectedPoints: ["The needle deflects", "Current produces magnetic effect", "Electricity and magnetism are connected"],
    misconceptionCheck: "Many students think current and magnetism are separate topics; this chapter connects them in the reverse direction too.",
  },
  teach: {
    teacherIntro: "Imagine you're under a coconut tree during the monsoon rain. As the rain falls on the coconut leaves, it makes the coconut tree move. Now, let's say we're holding a copper wire near the moving coconut tree. We'll get electricity! This is called electromagnetic induction.",
    explanationBlocks: [
      {
        heading: "The basic observation",
        explanation: "When a magnet is moved towards or away from a coil connected to a galvanometer, the galvanometer needle deflects. This shows current is induced in the coil.",
        keyTerms: ["magnet", "coil", "galvanometer", "induced current"],
      },
      {
        heading: "What must change",
        explanation: "The magnetic flux linked with the coil must change. A stationary magnet near a stationary coil does not keep producing induced current.",
        keyTerms: ["magnetic flux", "change", "relative motion"],
      },
      {
        heading: "How to increase the effect",
        explanation: "Move the magnet faster, use a stronger magnet, increase the number of turns in the coil, or use a soft iron core.",
        keyTerms: ["speed", "strong magnet", "turns", "soft iron core"],
      },
    ],
    analogy: "A changing magnetic field is like a moving hand pushing a swing. A still hand near the swing does not keep it moving.",
    malayalamSupport: "കാന്തിക ഫ്ലക്സിൽ മാറ്റം ഉണ്ടാകുമ്പോൾ കോയിലിൽ പ്രേരിത വൈദ്യുതധാര ഉണ്ടാകും. മാറ്റമാണ് പ്രധാന കാര്യം.",
    manglishSupport: "Magnetic flux change aakumbol coil-il induced current undaakum. Still magnet mathram pora; change venam.",
  },
  visualBoard: {
    boardTitle: "Magnet, coil and galvanometer",
    frames: [
      {
        id: "emi1-f1",
        title: "Move magnet into coil",
        teacherAction: "Draw a bar magnet moving towards a coil connected to a galvanometer.",
        boardText: ["Magnet moves in", "Flux linked with coil changes", "Galvanometer deflects"],
        diagramDescription: "Bar magnet arrow pointing into a coil, wire loop connected to a galvanometer.",
        studentFocus: "Current appears only while the magnetic field link is changing.",
      },
      {
        id: "emi1-f2",
        title: "Move magnet away",
        teacherAction: "Draw the magnet moving away and show the galvanometer deflecting to the opposite side.",
        boardText: ["Magnet moves away", "Flux changes in opposite way", "Induced current reverses direction"],
        diagramDescription: "Bar magnet arrow away from coil, galvanometer needle on the opposite side.",
        studentFocus: "Direction changes when the motion direction changes.",
      },
    ],
  },
  docDoeTrick: {
    title: "Change Makes Current",
    trick: "No change, no induced current.",
    whyItWorks: "Every induction answer starts with change in magnetic flux.",
  },
  keyNotes: [
          "Changing the magnetic field, like moving the coconut tree, can make a current in the wire.",
          "A moving magnet and a coil are like a dancer's hand moving in a circle. They can produce current without a battery.",
          "The galvanometer is like a speedometer in an auto rickshaw. It shows us if there's current and how much.",
          "If the coconut tree starts moving the other way, the current will change direction.",
          "If we make the coconut tree move faster, or use a stronger magnet, or add more turns to the coil, the current will get stronger."
        ],
  formulas: [],
  examAnswers: [
    {
      marks: 3,
      question: "What is electromagnetic induction? Write two ways to increase the induced current.",
      answerPoints: [
        "Electromagnetic induction is the production of induced current in a conductor due to change in magnetic flux linked with it.",
        "Induced current can be increased by moving the magnet/coil faster.",
        "It can also be increased by using a stronger magnet or increasing the number of turns in the coil.",
      ],
      keywords: ["induced current", "change in magnetic flux", "faster motion", "stronger magnet", "turns"],
      commonMistakes: ["Forgetting the word change", "Writing only magnet near coil"],
      boardStyleRewrite: "Electromagnetic induction is the production of induced current in a conductor when the magnetic flux linked with it changes. The induced current can be increased by faster motion, a stronger magnet, or more turns in the coil.",
    },
  ],
  yourTurn: {
    prompt: "In one sentence, explain why a stationary magnet near a stationary coil does not continuously produce current.",
    expectedAnswerPoints: ["No change in magnetic flux", "Induced current needs changing magnetic flux"],
    hint: "Use the word 'change'.",
  },
  correctionRubric: {
    maxMarks: 3,
    scoringPoints: [
      { point: "Defines induction", marks: 1, requiredKeywords: ["induced current"] },
      { point: "Mentions change in flux", marks: 1, requiredKeywords: ["change", "flux"] },
      { point: "Adds an increase method", marks: 1, requiredKeywords: ["faster", "turns", "magnet"] },
    ],
    commonMissingParts: ["change in magnetic flux", "increase methods"],
    feedbackTemplate: "You covered {covered}. Add {missing} for a complete induction answer.",
  },
  quiz: [
    {
      id: "emi1-q1",
      type: "mcq",
      question: "The essential condition for electromagnetic induction is",
      options: ["constant current", "change in magnetic flux", "high resistance", "a hot conductor"],
      answer: "change in magnetic flux",
      explanation: "Induced current is produced when magnetic flux linked with a conductor changes.",
      difficulty: "easy",
      tags: ["induction"],
    },
    {
      id: "emi1-q2",
      type: "short",
      question: "Name the instrument used to detect the small induced current in the coil experiment.",
      answer: "Galvanometer",
      explanation: "A galvanometer shows deflection when induced current flows.",
      difficulty: "easy",
      tags: ["galvanometer"],
    },
  ],
  recap: {
    summary: [
              "To make electricity with induction, we need to change the magnetic field.",
              "The galvanometer helps us see if there's current, and it shows us how much.",
              "If the coconut tree (or magnet) changes direction, the current will change direction too."
            ],
    mustRemember: ["Change in magnetic flux = induced current"],
  },
  revisionSave: {
    flashcards: [
      { front: "Electromagnetic induction?", back: "Production of induced current due to change in magnetic flux." },
      { front: "No change in flux means?", back: "No continuous induced current." },
      { front: "Detect induced current using?", back: "Galvanometer." },
    ],
    revisionNotes: ["Practice magnet-coil-galvanometer diagram", "Memorise 'change in magnetic flux'"],
    weakAreaTags: ["electromagnetic induction", "magnetic flux", "galvanometer"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M2: TuitionLessonSeed = emiSeed({
  missionId: "M2",
  missionTitle: "Direction of Induced Current and AC",
  goal: "Connect direction of motion, direction of induced current and alternating current.",
  estimatedMinutes: 30,
  contentType: "concept",
  tags: ["induced current direction", "alternating current", "AC", "DC", "magnetic flux"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "When the magnet is moved into a coil and then moved out, does the galvanometer deflect to the same side both times?",
    expectedPoints: ["No", "It deflects in opposite directions", "Current direction changes"],
    misconceptionCheck: "Students often remember only 'current is produced' and forget that its direction depends on the change.",
  },
  teach: {
    teacherIntro: "Imagine running a coconut tree farm. When the wind blows from one side, the coconut trees sway in one direction. But when the wind blows from the opposite side, the coconuts sway in the opposite direction. This is like what happens with currents when the direction of motion or magnetic field is reversed.",
    explanationBlocks: [
      {
        heading: "Forward motion",
        explanation: "When the magnet moves towards the coil, magnetic flux through the coil changes in one way and the galvanometer deflects to one side.",
        keyTerms: ["towards coil", "one direction", "galvanometer deflection"],
      },
      {
        heading: "Reverse motion",
        explanation: "When the magnet is moved away from the coil, the flux change is reversed, so the induced current direction also reverses.",
        keyTerms: ["away from coil", "opposite direction", "reversal"],
      },
      {
        heading: "Alternating current idea",
        explanation: "If the direction of current changes continuously at regular intervals, it is alternating current. A rotating generator coil produces this kind of current.",
        keyTerms: ["alternating current", "regular reversal", "generator"],
      },
    ],
    analogy: "Push a door in, it swings one way. Pull it out, it swings back. In induction, reversing the change reverses current.",
    malayalamSupport: "കാന്തം കോയിലിലേക്ക് നീക്കുമ്പോഴും പുറത്തേക്ക് നീക്കുമ്പോഴും പ്രേരിത വൈദ്യുതധാരയുടെ ദിശ മാറും.",
    manglishSupport: "Magnet innum outum move cheyyumbol current direction marum. Regular reversal aanu AC.",
  },
  visualBoard: {
    boardTitle: "Direction reversal board",
    frames: [
      {
        id: "emi2-f1",
        title: "Motion into coil",
        teacherAction: "Draw magnet moving into coil and needle to the right.",
        boardText: ["Motion: into coil", "Induced current: one direction", "Needle: right"],
        diagramDescription: "Magnet arrow entering coil, galvanometer needle right.",
        studentFocus: "One flux-change direction gives one current direction.",
      },
      {
        id: "emi2-f2",
        title: "Motion out of coil",
        teacherAction: "Draw magnet moving out and needle to the left.",
        boardText: ["Motion: away from coil", "Induced current: opposite direction", "Needle: left"],
        diagramDescription: "Magnet arrow leaving coil, galvanometer needle left.",
        studentFocus: "Reverse motion reverses current.",
      },
      {
        id: "emi2-f3",
        title: "AC pattern",
        teacherAction: "Draw a simple wave crossing a zero line.",
        boardText: ["Current reverses repeatedly", "This is alternating current (AC)"],
        diagramDescription: "Sine-like wave above and below a center line.",
        studentFocus: "AC is repeated reversal, not just one-time reversal.",
      },
    ],
  },
  docDoeTrick: {
    title: "Reverse Change, Reverse Current",
    trick: "Motion reversed means current reversed.",
    whyItWorks: "It links the galvanometer experiment directly to AC generator output.",
  },
  keyNotes: [
          "The direction of the current depends on how the magnetic field is changing.",
          "Think of riding an auto-rickshaw through a football stadium. When you drive in one direction, the ball (magnetic field) deflects in one direction. But when you drive in the opposite direction, the ball deflects in the opposite direction.",
          "Now imagine watching a galvanometer (football match) on TV. If the match changes direction (magnetic field changes direction) many times in a short time, it will look like the ball is moving in different directions, changing quickly. This is like alternating current (AC).",
          "A generator is like a big machine that makes power continuously. When the coil inside the machine rotates with a special system (slip rings), the generator produces AC power.",
          "But a cell (like a battery) gives power in one direction only because the direction of the magnetic field doesn't change."
        ],
  formulas: [],
  examAnswers: [
    {
      marks: 2,
      question: "Why does the galvanometer deflect in opposite directions when a magnet is moved into and out of a coil?",
      answerPoints: [
        "The direction of change in magnetic flux is opposite in the two cases.",
        "So the direction of induced current is also reversed.",
      ],
      keywords: ["opposite", "magnetic flux", "induced current", "direction"],
      commonMistakes: ["Writing only 'because magnet moves'", "Not mentioning direction of flux change"],
      boardStyleRewrite: "When the magnet is moved into and out of the coil, the change in magnetic flux occurs in opposite directions. Therefore the induced current also reverses, so the galvanometer deflects oppositely.",
    },
  ],
  yourTurn: {
    prompt: "Write one difference between AC and DC.",
    expectedAnswerPoints: ["AC changes direction periodically", "DC flows in one direction"],
    hint: "Use direction of current.",
  },
  correctionRubric: {
    maxMarks: 2,
    scoringPoints: [
      { point: "AC direction reversal", marks: 1, requiredKeywords: ["changes", "direction"] },
      { point: "DC one direction", marks: 1, requiredKeywords: ["one", "direction"] },
    ],
    commonMissingParts: ["direction", "periodic reversal"],
    feedbackTemplate: "Good start with {covered}. Add {missing} to compare AC and DC clearly.",
  },
  quiz: [
    {
      id: "emi2-q1",
      type: "mcq",
      question: "Current that changes direction at regular intervals is called",
      options: ["direct current", "alternating current", "static current", "short circuit"],
      answer: "alternating current",
      explanation: "AC reverses direction periodically.",
      difficulty: "easy",
      tags: ["AC"],
    },
    {
      id: "emi2-q2",
      type: "short",
      question: "What happens to induced current when the magnet motion is reversed?",
      answer: "The direction of induced current reverses.",
      explanation: "Reversing the flux change reverses the current direction.",
      difficulty: "easy",
      tags: ["direction"],
    },
  ],
  recap: {
    summary: [
              "The direction of the current is controlled by how the magnetic field is changing.",
              "If you move the magnet (galvanometer ball) in one direction, it will deflect in one direction. But if you move it in the opposite direction, it will deflect in the opposite direction.",
              "AC means the current changes direction many times at regular intervals, like a football match changing direction quickly."
            ],
    mustRemember: ["Reverse change -> reverse current"],
  },
  revisionSave: {
    flashcards: [
      { front: "AC?", back: "Current that changes direction periodically." },
      { front: "DC?", back: "Current flowing in one direction." },
      { front: "Reverse magnet motion?", back: "Reverse induced current direction." },
    ],
    revisionNotes: ["Practice one AC/DC comparison answer", "Draw opposite galvanometer deflections"],
    weakAreaTags: ["AC", "DC", "induced current direction"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M3: TuitionLessonSeed = emiSeed({
  missionId: "M3",
  missionTitle: "AC and DC Generators",
  goal: "Explain generator principle, parts and AC/DC output using slip rings and split rings.",
  estimatedMinutes: 35,
  contentType: "diagram",
  tags: ["generator", "AC generator", "DC generator", "armature", "field magnet", "slip ring", "split ring"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "Which phenomenon is used in generators to produce current?",
    expectedPoints: ["Electromagnetic induction", "Change in magnetic flux", "Rotating coil in magnetic field"],
    misconceptionCheck: "A generator does not store electricity like a battery; it converts mechanical energy into electrical energy.",
  },
  teach: {
    teacherIntro: "Think of a coconut tree swaying in the monsoon wind. A generator works like that, it takes the energy from moving things and turns it into electricity. This magic is called electromagnetic induction!",
    explanationBlocks: [
      {
        heading: "Main parts",
        explanation: "The main parts are field magnet, armature/coil, rings and brushes. Rotation changes magnetic flux through the coil.",
        keyTerms: ["field magnet", "armature", "rings", "brushes"],
      },
      {
        heading: "AC generator",
        explanation: "In an AC generator, slip rings keep the coil ends connected so the external current reverses direction each half turn.",
        keyTerms: ["AC generator", "slip rings", "alternating current"],
      },
      {
        heading: "DC generator",
        explanation: "In a DC generator, split rings reverse the connection every half turn, helping the external current remain in one direction.",
        keyTerms: ["DC generator", "split rings", "direct current"],
      },
    ],
    analogy: "A generator is like a bicycle dynamo: rotation is the input, electrical energy is the output.",
    malayalamSupport: "ജനറേറ്റർ യാന്ത്രിക ഊർജം വൈദ്യുത ഊർജമാക്കി മാറ്റുന്നു. അടിസ്ഥാന തത്വം electromagnetic induction ആണ്.",
    manglishSupport: "Generator mechanical energy-ne electrical energy aakkum. Principle: electromagnetic induction.",
  },
  visualBoard: {
    boardTitle: "Generator parts and output",
    frames: [
      {
        id: "emi3-f1",
        title: "Generator principle",
        teacherAction: "Draw a rectangular coil rotating between N and S poles.",
        boardText: ["Rotating coil", "Changing magnetic flux", "Induced current"],
        diagramDescription: "Coil between field magnet poles with rotation arrow and output wires.",
        studentFocus: "Rotation creates changing flux.",
      },
      {
        id: "emi3-f2",
        title: "AC generator parts",
        teacherAction: "Label slip rings and brushes on the rotating coil.",
        boardText: ["Slip rings", "Brushes", "Output: AC"],
        diagramDescription: "Two continuous rings connected to coil ends, brushes touching rings.",
        studentFocus: "Slip rings give alternating output.",
      },
      {
        id: "emi3-f3",
        title: "DC generator parts",
        teacherAction: "Replace slip rings with a split ring commutator.",
        boardText: ["Split ring", "Brushes", "Output: DC"],
        diagramDescription: "Split-ring commutator connected to coil ends.",
        studentFocus: "Split ring changes the external connection each half turn.",
      },
    ],
  },
  docDoeTrick: {
    title: "Slip for AC, Split for DC",
    trick: "Slip ring slips AC out; split ring straightens DC.",
    whyItWorks: "It ties each ring type to the current output examiners expect.",
  },
  keyNotes: [
          "A generator works like an auto rickshaw, it uses electromagnetic induction to move, like when you pedal a bike",
          "It takes energy from things that move, like a football player running, and turns it into electricity for our homes to light up",
          "The field magnet is like a strong tree, it gives a steady magnetic field like a calm lake",
          "The armature is like a rotating fan, it changes the magnetic flux as it moves, like when you turn on a ceiling fan",
          "Slip rings are like a special switch, they help give us AC electricity, and split rings help give us DC electricity, like choosing a special recipe for our gadgets"
        ],
  formulas: [],
  examAnswers: [
    {
      marks: 4,
      question: "Write the principle and main parts of an AC generator.",
      answerPoints: [
        "The principle is electromagnetic induction.",
        "When the armature coil rotates in a magnetic field, magnetic flux linked with it changes and current is induced.",
        "Main parts are field magnet, armature, slip rings and brushes.",
        "The output current is alternating current.",
      ],
      keywords: ["electromagnetic induction", "armature", "field magnet", "slip rings", "brushes", "AC"],
      commonMistakes: ["Writing split ring for AC generator", "Forgetting energy transformation"],
      boardStyleRewrite: "An AC generator works on electromagnetic induction. As the armature coil rotates between the poles of a field magnet, the magnetic flux linked with the coil changes and current is induced. Its main parts are field magnet, armature, slip rings and brushes. The output is alternating current.",
    },
  ],
  yourTurn: {
    prompt: "Write the energy transformation in a generator.",
    expectedAnswerPoints: ["Mechanical energy to electrical energy"],
    hint: "Start from rotation.",
  },
  correctionRubric: {
    maxMarks: 4,
    scoringPoints: [
      { point: "Principle", marks: 1, requiredKeywords: ["electromagnetic induction"] },
      { point: "Flux change by rotation", marks: 1, requiredKeywords: ["rotates", "flux"] },
      { point: "Main parts", marks: 1, requiredKeywords: ["field magnet", "armature"] },
      { point: "Slip rings/AC", marks: 1, requiredKeywords: ["slip", "AC"] },
    ],
    commonMissingParts: ["slip rings", "armature", "energy transformation"],
    feedbackTemplate: "You have {covered}. Add {missing} for the full generator answer.",
  },
  quiz: [
    {
      id: "emi3-q1",
      type: "mcq",
      question: "The ring used in an AC generator is",
      options: ["split ring", "slip ring", "fuse wire", "earth wire"],
      answer: "slip ring",
      explanation: "AC generator uses slip rings; DC generator uses split rings.",
      difficulty: "easy",
      tags: ["generator"],
    },
    {
      id: "emi3-q2",
      type: "diagram",
      question: "Name two parts to label in a generator diagram.",
      answer: "Field magnet and armature",
      explanation: "Other valid labels include rings and brushes.",
      difficulty: "medium",
      tags: ["diagram"],
    },
  ],
  recap: {
    summary: [
              "A generator is like a cook, it uses electromagnetic induction to make electricity, just like cooking rice from raw grains",
              "It takes mechanical energy, like the energy from a bicycle, and turns it into electrical energy for our use, like filling up our phone batteries",
              "Slip rings are like an AC switch, they help give us AC electricity, and split rings are like a DC switch, they help give us DC electricity, like choosing a special menu for our devices"
            ],
    mustRemember: ["Slip = AC; split = DC"],
  },
  revisionSave: {
    flashcards: [
      { front: "Generator principle?", back: "Electromagnetic induction." },
      { front: "AC generator ring?", back: "Slip ring." },
      { front: "DC generator ring?", back: "Split ring." },
    ],
    revisionNotes: ["Draw AC generator once", "Write AC vs DC ring comparison"],
    weakAreaTags: ["generator", "slip ring", "split ring"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M4: TuitionLessonSeed = emiSeed({
  missionId: "M4",
  missionTitle: "Transformers and Voltage Change",
  goal: "Use transformer structure and turns ratio to explain step-up and step-down transformers.",
  estimatedMinutes: 35,
  contentType: "numerical",
  tags: ["transformer", "step-up", "step-down", "primary coil", "secondary coil", "turns ratio"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "Which current is needed for a transformer to work: AC or DC?",
    expectedPoints: ["AC", "Changing current", "Changing magnetic field"],
    misconceptionCheck: "A transformer needs changing magnetic flux, so steady DC will not work in the normal transformer action.",
  },
  teach: {
    teacherIntro: "Envision a transformer like an auto rickshaw that assists in changing the 'speed' of electricity. It utilises a special helper called mutual induction between two coils on a soft iron core, much like a coconut tree provides shade to two people sitting under it.",
    explanationBlocks: [
      {
        heading: "Parts",
        explanation: "A transformer has primary coil, secondary coil and a laminated soft iron core. AC in the primary produces changing magnetic flux in the core.",
        keyTerms: ["primary coil", "secondary coil", "soft iron core"],
      },
      {
        heading: "Step-up transformer",
        explanation: "If the secondary has more turns than the primary, the output voltage is higher. This is a step-up transformer.",
        keyTerms: ["step-up", "more secondary turns", "higher voltage"],
      },
      {
        heading: "Step-down transformer",
        explanation: "If the secondary has fewer turns than the primary, the output voltage is lower. This is a step-down transformer.",
        keyTerms: ["step-down", "fewer secondary turns", "lower voltage"],
      },
    ],
    analogy: "Turns are like gear size: more secondary turns can raise voltage; fewer secondary turns lower it.",
    malayalamSupport: "ട്രാൻസ്ഫോർമർ AC voltage മാറ്റാൻ ഉപയോഗിക്കുന്നു. Secondary turns കൂടുതലെങ്കിൽ step-up, കുറവെങ്കിൽ step-down.",
    manglishSupport: "Transformer AC voltage maattan aanu. Secondary turns kooduthal aanenkil step-up; kurav aanenkil step-down.",
  },
  visualBoard: {
    boardTitle: "Transformer turns ratio",
    frames: [
      {
        id: "emi4-f1",
        title: "Transformer parts",
        teacherAction: "Draw primary and secondary coils on a soft iron core.",
        boardText: ["Primary coil: input", "Secondary coil: output", "Soft iron core: flux path"],
        diagramDescription: "Two coils wound on opposite limbs of a rectangular core.",
        studentFocus: "Voltage change happens through mutual induction.",
      },
      {
        id: "emi4-f2",
        title: "Step-up vs step-down",
        teacherAction: "Write Ns > Np and Ns < Np cases.",
        boardText: ["Ns > Np -> Vs > Vp (step-up)", "Ns < Np -> Vs < Vp (step-down)"],
        diagramDescription: "Two side-by-side transformer sketches with more/fewer secondary turns.",
        studentFocus: "Compare turns first, then voltage.",
      },
      {
        id: "emi4-f3",
        title: "Numerical frame",
        teacherAction: "Set up Vs/Vp = Ns/Np and show cross multiplication.",
        boardText: ["Vs/Vp = Ns/Np", "Substitute known values", "Cross-multiply"],
        diagramDescription: "Formula triangle style board for transformer ratio.",
        studentFocus: "Keep voltage with voltage and turns with turns.",
      },
    ],
  },
  docDoeTrick: {
    title: "Secondary Decides Output",
    trick: "More secondary turns means more secondary voltage.",
    whyItWorks: "Transformer questions usually ask output voltage or transformer type; compare secondary turns immediately.",
  },
  keyNotes: [
          "A transformer works like a friend helping another friend, using mutual induction.",
          "It functions with AC electricity since the current changing creates a changing magnetic flux, similar to monsoon rain filling up a river.",
          "The primary coil is like the driver who receives the input, while the secondary coil is like the passenger who receives the output.",
          "A step-up transformer is like a big ladder, having more steps in the secondary coil than the primary coil.",
          "A step-down transformer is like a small stool, having fewer steps in the secondary coil than the primary coil."
        ],
  formulas: [transformerFormula],
  examAnswers: [
    {
      marks: 4,
      question: "Differentiate between step-up and step-down transformers.",
      answerPoints: [
        "A step-up transformer increases AC voltage.",
        "In a step-up transformer, the secondary coil has more turns than the primary coil.",
        "A step-down transformer decreases AC voltage.",
        "In a step-down transformer, the secondary coil has fewer turns than the primary coil.",
      ],
      keywords: ["step-up", "step-down", "secondary turns", "primary turns", "voltage"],
      commonMistakes: ["Comparing current instead of turns", "Forgetting transformer works with AC"],
      boardStyleRewrite: "A step-up transformer increases AC voltage and has more turns in the secondary coil than in the primary. A step-down transformer decreases AC voltage and has fewer turns in the secondary coil than in the primary.",
    },
  ],
  yourTurn: {
    prompt: "A transformer has Vp = 240 V, Np = 4000 turns and Vs = 12 V. Find Ns.",
    expectedAnswerPoints: ["12/240 = Ns/4000", "Ns = 200 turns"],
    hint: "Use Vs/Vp = Ns/Np.",
  },
  correctionRubric: {
    maxMarks: 4,
    scoringPoints: [
      { point: "Writes formula", marks: 1, requiredKeywords: ["Vs", "Vp", "Ns", "Np"] },
      { point: "Substitutes values", marks: 1, requiredKeywords: ["12", "240", "4000"] },
      { point: "Calculates turns", marks: 1, requiredKeywords: ["200"] },
      { point: "Adds unit/context", marks: 1, requiredKeywords: ["turns", "step-down"] },
    ],
    commonMissingParts: ["turns unit", "correct substitution order"],
    feedbackTemplate: "You solved {covered}. Fix {missing} to secure all marks.",
  },
  quiz: [
    {
      id: "emi4-q1",
      type: "numerical",
      question: "In a transformer, Vp = 100 V, Np = 200 turns and Ns = 400 turns. Find Vs.",
      answer: "Vs = 200 volt",
      explanation: "Vs/Vp = Ns/Np, so Vs/100 volt = 400/200 = 2; Vs = 200 volt.",
      difficulty: "medium",
      tags: ["transformer numerical"],
    },
    {
      id: "emi4-q2",
      type: "mcq",
      question: "A transformer with secondary turns more than primary turns is",
      options: ["step-down transformer", "step-up transformer", "fuse", "ELCB"],
      answer: "step-up transformer",
      explanation: "More secondary turns gives higher secondary voltage.",
      difficulty: "easy",
      tags: ["transformer"],
    },
  ],
  recap: {
    summary: [
              "A transformer changes AC voltage like a cook adjusting the amount of spice in a dish.",
              "Use a simple formula: output voltage/input voltage = number of turns in secondary coil/number of turns in primary coil, like a recipe to get the right taste.",
              "The number of turns in the secondary coil determines if it's step-up or step-down, like a football team deciding to play offence or defence."
            ],
    mustRemember: ["More secondary turns -> step-up"],
  },
  revisionSave: {
    flashcards: [
      { front: "Transformer formula?", back: "Vs/Vp = Ns/Np." },
      { front: "Step-up condition?", back: "Ns > Np." },
      { front: "Step-down condition?", back: "Ns < Np." },
    ],
    revisionNotes: ["Practice one turns-ratio numerical", "Draw primary/secondary/core labels"],
    weakAreaTags: ["transformer", "turns ratio", "step-up", "step-down"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M5: TuitionLessonSeed = emiSeed({
  missionId: "M5",
  missionTitle: "Power Transmission from Station to Home",
  goal: "Explain why electricity is transmitted at high voltage and stepped down before use.",
  estimatedMinutes: 35,
  contentType: "formula",
  tags: ["power transmission", "high voltage", "heat loss", "step-up transformer", "step-down transformer", "P=VI"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "In Joule heating, what happens to heat loss when current becomes large?",
    expectedPoints: ["Heat loss increases", "H is proportional to I squared", "Large current wastes energy"],
    misconceptionCheck: "Students sometimes think higher current is always better for transmission; high current causes more heat loss.",
  },
  teach: {
    teacherIntro: "Imagine you are carrying water from a well to your home in a bucket tied to a stick. If you carry water in a high-pressure hose, you need to use less effort to carry the water. In the same way, electric power is sent through high voltage lines, so the current (like the water flow) becomes small. This reduces heat loss in the long transmission lines.",
    explanationBlocks: [
      {
        heading: "Power relation",
        explanation: "For a fixed power, P = VI. If voltage is increased, current decreases.",
        keyTerms: ["P = VI", "high voltage", "low current"],
      },
      {
        heading: "Heat loss relation",
        explanation: "Heat loss in transmission wires depends strongly on current. Lower current means lower heat loss.",
        keyTerms: ["heat loss", "current", "transmission wires"],
      },
      {
        heading: "Voltage stages",
        explanation: "Voltage is stepped up near the generating station for long-distance transmission and stepped down near consumers for safe use.",
        keyTerms: ["step-up", "long-distance transmission", "step-down", "230 V household supply"],
      },
    ],
    analogy: "Transporting power at high voltage is like carrying water through a wider pipe with less friction loss.",
    malayalamSupport: "ദൂരേക്ക് വൈദ്യുതി അയയ്ക്കുമ്പോൾ voltage കൂട്ടുന്നു. അപ്പോൾ current കുറയും, heat loss കുറയും.",
    manglishSupport: "Long distance transmission-il voltage koottum. Same power-il current kurayum, heat loss kurayum.",
  },
  visualBoard: {
    boardTitle: "Power station to home",
    frames: [
      {
        id: "emi5-f1",
        title: "Step-up at station",
        teacherAction: "Draw generating station, step-up transformer and transmission lines.",
        boardText: ["Generated voltage", "Step-up transformer", "High-voltage transmission"],
        diagramDescription: "Power station connected to transformer and tall transmission towers.",
        studentFocus: "Voltage is raised before long-distance travel.",
      },
      {
        id: "emi5-f2",
        title: "Current and heat loss",
        teacherAction: "Write P = VI and show V up means I down for same P.",
        boardText: ["For same P: V increases -> I decreases", "Lower I -> lower heat loss"],
        diagramDescription: "Simple proportional board with voltage arrow up and current arrow down.",
        studentFocus: "High voltage is used to reduce current.",
      },
      {
        id: "emi5-f3",
        title: "Step-down near home",
        teacherAction: "Draw local transformer reducing voltage before house supply.",
        boardText: ["Step-down transformer", "Safe household voltage", "Distribution to homes"],
        diagramDescription: "Transformer near houses with supply lines entering a home.",
        studentFocus: "Voltage must be reduced before domestic use.",
      },
    ],
  },
  docDoeTrick: {
    title: "High V, Low I, Low Loss",
    trick: "HVLL: High Voltage, Low Loss.",
    whyItWorks: "It compresses the whole transmission answer into the mark-scoring chain.",
  },
  keyNotes: [
          "For sending power, we use high voltage like a super highway.",
          "For the same amount of power, if you increase the voltage, the current becomes low.",
          "Lower current means less heat loss in the long transmission lines like a cool breeze on a hot day.",
          "Near the power stations, we use step-up transformers like a super-powerful pump to increase the voltage.",
          "Near your home, we use step-down transformers like a gentle shower to decrease the voltage for domestic supply."
        ],
  formulas: [powerTransmissionFormula, currentFormula],
  examAnswers: [
    {
      marks: 4,
      question: "Why is electric power transmitted at high voltage?",
      answerPoints: [
        "For a fixed power, P = VI.",
        "When voltage is increased, current decreases.",
        "Heat loss in transmission lines depends on current, so lower current reduces heat loss.",
        "Therefore step-up transformers are used for long-distance transmission and step-down transformers before domestic supply.",
      ],
      keywords: ["high voltage", "low current", "heat loss", "P = VI", "step-up", "step-down"],
      commonMistakes: ["Writing only 'to save electricity'", "Not connecting voltage, current and heat loss"],
      boardStyleRewrite: "Electric power is transmitted at high voltage because for the same power, P = VI. Increasing voltage reduces current. Since heat loss in transmission lines increases with current, low current reduces energy loss. Hence voltage is stepped up for transmission and stepped down for domestic use.",
    },
  ],
  yourTurn: {
    prompt: "For the same power, if transmission voltage is increased, what happens to current and heat loss?",
    expectedAnswerPoints: ["Current decreases", "Heat loss decreases"],
    hint: "Use P = VI.",
  },
  correctionRubric: {
    maxMarks: 4,
    scoringPoints: [
      { point: "Uses P = VI", marks: 1, requiredKeywords: ["P", "VI"] },
      { point: "Voltage-current relation", marks: 1, requiredKeywords: ["voltage", "current"] },
      { point: "Heat loss explanation", marks: 1, requiredKeywords: ["heat", "loss"] },
      { point: "Transformer stages", marks: 1, requiredKeywords: ["step-up", "step-down"] },
    ],
    commonMissingParts: ["P = VI", "current decreases", "step-up/step-down stages"],
    feedbackTemplate: "You explained {covered}. Add {missing} for the full transmission chain.",
  },
  quiz: [
    {
      id: "emi5-q1",
      type: "mcq",
      question: "For the same power, increasing transmission voltage will",
      options: ["increase current", "decrease current", "stop current", "increase resistance"],
      answer: "decrease current",
      explanation: "P = VI, so if P is fixed and V increases, I decreases.",
      difficulty: "easy",
      tags: ["transmission"],
    },
    {
      id: "emi5-q2",
      type: "short",
      question: "Which transformer is used near the generating station for transmission?",
      answer: "Step-up transformer",
      explanation: "It increases voltage before long-distance transmission.",
      difficulty: "easy",
      tags: ["step-up"],
    },
  ],
  recap: {
    summary: [
              "Transmission uses high voltage to carry power like a super highway.",
              "High voltage makes the current low like a cool breeze.",
              "Lower current reduces heat loss like a refreshing rain on a hot summer day."
            ],
    mustRemember: ["High V -> Low I -> Low heat loss"],
  },
  revisionSave: {
    flashcards: [
      { front: "Transmission formula?", back: "P = VI." },
      { front: "Why high voltage?", back: "To reduce current and heat loss." },
      { front: "Transformer near station?", back: "Step-up transformer." },
    ],
    revisionNotes: ["Practice 4-mark high-voltage answer", "Draw power station to home flow"],
    weakAreaTags: ["power transmission", "heat loss", "P=VI"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M6: TuitionLessonSeed = emiSeed({
  missionId: "M6",
  missionTitle: "Domestic Wiring and Safety Devices",
  goal: "Explain household distribution, fuse/MCB, earthing, three-pin plug and ELCB safety.",
  estimatedMinutes: 35,
  contentType: "diagram",
  tags: ["domestic wiring", "fuse", "MCB", "earthing", "three-pin plug", "ELCB", "short circuit"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "Why should the metallic body of an electric iron or mixer be connected to earth wire?",
    expectedPoints: ["To avoid electric shock", "Fault current gets a safe path to earth", "Safety"],
    misconceptionCheck: "Students often confuse neutral and earth. Earth is a safety path, not the normal return path.",
  },
  teach: {
    teacherIntro: "Just like water flowing through pipes to your home, electricity flows through wires to your appliances. We use live, neutral, and earth wires with special guards to keep you safe.",
    explanationBlocks: [
      {
        heading: "Main parts of household supply",
        explanation: "Supply reaches the house through a watt-hour meter, main switch and distribution circuits. Appliances are usually connected in parallel.",
        keyTerms: ["watt-hour meter", "main switch", "parallel connection"],
      },
      {
        heading: "Fuse and MCB",
        explanation: "A fuse or MCB protects a circuit from excess current caused by overload or short circuit.",
        keyTerms: ["fuse", "MCB", "overload", "short circuit"],
      },
      {
        heading: "Earthing and ELCB",
        explanation: "Earth wire gives leakage current a safe path. ELCB disconnects supply when leakage to earth is detected.",
        keyTerms: ["earthing", "three-pin plug", "leakage current", "ELCB"],
      },
    ],
    analogy: "Fuse/MCB is like a guard at the gate; earthing is like an emergency drain for dangerous leakage current.",
    malayalamSupport: "Earth wire shock ഒഴിവാക്കാൻ സുരക്ഷാ വഴിയാണ്. Fuse/MCB excess current വന്നാൽ circuit break ചെയ്യും.",
    manglishSupport: "Earth wire shock avoid cheyyan safety path aanu. Fuse/MCB excess current vannal circuit break cheyyum.",
  },
  visualBoard: {
    boardTitle: "Domestic wiring safety board",
    frames: [
      {
        id: "emi6-f1",
        title: "House supply flow",
        teacherAction: "Draw supply line entering watt-hour meter, main switch and distribution board.",
        boardText: ["Supply line", "Watt-hour meter", "Main switch", "Distribution circuits"],
        diagramDescription: "Simple home wiring flow from supply line to meter, main switch and circuits.",
        studentFocus: "Meter measures energy; main switch controls supply.",
      },
      {
        id: "emi6-f2",
        title: "Fuse/MCB position",
        teacherAction: "Mark fuse/MCB in the live line.",
        boardText: ["Excess current", "Fuse melts / MCB trips", "Circuit opens"],
        diagramDescription: "Circuit line with fuse/MCB symbol opening during overload.",
        studentFocus: "Safety device breaks the circuit during danger.",
      },
      {
        id: "emi6-f3",
        title: "Three-pin plug and earth",
        teacherAction: "Draw live, neutral and earth pins; connect earth to metal body.",
        boardText: ["Live", "Neutral", "Earth", "Earth -> metal body"],
        diagramDescription: "Three-pin plug labels and an appliance body connected to earth wire.",
        studentFocus: "Earth wire protects the user from shock.",
      },
    ],
  },
  docDoeTrick: {
    title: "F-M-E Safety Chain",
    trick: "Fuse/MCB cuts; Earth carries; ELCB catches leakage.",
    whyItWorks: "It keeps the three safety roles separate in exam answers.",
  },
  keyNotes: [
          "Think of many appliances connected to the same electricity supply like friends sitting together in a football stadium. Each one gets the same voltage, like the same amount of energy.",
          "Just like a traffic cop controls traffic, fuse and MCB control the flow of electricity to prevent excess current.",
          "Imagine excess current like a burst pipe. Short circuit and overload can cause such bursts, which we need to prevent.",
          "The earth wire is like a strong rope tied to the metal body of appliances to keep you safe from shock. If you touch a live wire, the earth wire pulls you to safety.",
          "ELCB is like a clever sensor that checks if there's a leakage of electricity to the earth. If it finds one, it disconnects the supply immediately."
        ],
  formulas: [],
  examAnswers: [
    {
      marks: 4,
      question: "Explain the role of fuse/MCB and earthing in domestic wiring.",
      answerPoints: [
        "Fuse or MCB protects the circuit from excess current due to overload or short circuit.",
        "A fuse melts or an MCB trips and breaks the circuit.",
        "Earthing connects the metallic body of appliances to earth.",
        "If leakage occurs, current flows safely to earth and electric shock is avoided.",
      ],
      keywords: ["fuse", "MCB", "excess current", "short circuit", "earthing", "electric shock"],
      commonMistakes: ["Saying earth wire carries normal current", "Forgetting short circuit or overload"],
      boardStyleRewrite: "Fuse/MCB protects a domestic circuit from excess current caused by overload or short circuit by breaking the circuit. Earthing connects the metallic body of appliances to earth, giving leakage current a safe path and preventing electric shock.",
    },
  ],
  yourTurn: {
    prompt: "Write two causes of excess current in a domestic circuit.",
    expectedAnswerPoints: ["Overload", "Short circuit"],
    hint: "One starts with O, one starts with S.",
  },
  correctionRubric: {
    maxMarks: 4,
    scoringPoints: [
      { point: "Fuse/MCB function", marks: 1, requiredKeywords: ["excess", "current"] },
      { point: "Breaks circuit", marks: 1, requiredKeywords: ["breaks", "trips", "melts"] },
      { point: "Earthing function", marks: 1, requiredKeywords: ["earth", "metallic"] },
      { point: "Shock safety", marks: 1, requiredKeywords: ["shock", "leakage"] },
    ],
    commonMissingParts: ["overload/short circuit", "leakage path", "metallic body"],
    feedbackTemplate: "You wrote {covered}. Add {missing} to make the safety answer complete.",
  },
  quiz: [
    {
      id: "emi6-q1",
      type: "mcq",
      question: "The earth wire in a three-pin plug is mainly for",
      options: ["measuring power", "safety from electric shock", "increasing voltage", "reducing bill"],
      answer: "safety from electric shock",
      explanation: "It gives leakage current a safe path to earth.",
      difficulty: "easy",
      tags: ["earthing"],
    },
    {
      id: "emi6-q2",
      type: "short",
      question: "Name two causes of excess current.",
      answer: "Overload and short circuit",
      explanation: "Both can make current exceed the safe limit.",
      difficulty: "easy",
      tags: ["safety"],
    },
  ],
  recap: {
    summary: [
              "Fuse/MCB is like a guardian that saves you from excess current.",
              "The earth wire is like a shield that keeps you safe from shock.",
              "ELCB is like a quick responder that detects leakage to earth and stops the supply."
            ],
    mustRemember: ["Fuse cuts, earth protects, ELCB detects leakage"],
  },
  revisionSave: {
    flashcards: [
      { front: "Two causes of excess current?", back: "Overload and short circuit." },
      { front: "Earth wire role?", back: "Safety path for leakage current." },
      { front: "ELCB role?", back: "Disconnects supply during earth leakage." },
    ],
    revisionNotes: ["Draw three-pin plug labels", "Write fuse/MCB vs earthing comparison"],
    weakAreaTags: ["domestic wiring", "fuse", "earthing", "ELCB"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M7: TuitionLessonSeed = emiSeed({
  missionId: "M7",
  missionTitle: "Exam Answer Practice - Electromagnetic Induction",
  goal: "Convert EMI, generator, transformer and domestic wiring ideas into mark-scoring answers.",
  estimatedMinutes: 35,
  contentType: "exam_answer",
  tags: ["exam answer", "generator", "transformer", "transmission", "domestic wiring", "keywords"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "Write the two words that must appear in an electromagnetic induction definition.",
    expectedPoints: ["Induced current", "Change in magnetic flux"],
    misconceptionCheck: "Long answers lose marks if the keyword 'change' is missing.",
  },
  teach: {
    teacherIntro: "Good news, friends! When you explain EMI in a clear way, with the principle, part name, and reason chain, you get good marks.",
    explanationBlocks: [
      {
        heading: "Induction answer structure",
        explanation: "Start with change in magnetic flux, then induced current, then one condition or increase method.",
        keyTerms: ["magnetic flux", "induced current", "increase methods"],
      },
      {
        heading: "Generator answer structure",
        explanation: "Write principle, energy transformation, parts and output type. Mention slip rings for AC and split ring for DC.",
        keyTerms: ["principle", "energy transformation", "slip ring", "split ring"],
      },
      {
        heading: "Transmission and safety structure",
        explanation: "For high-voltage transmission, write P = VI -> current decreases -> heat loss decreases. For safety, separate fuse/MCB, earth wire and ELCB roles.",
        keyTerms: ["P = VI", "heat loss", "fuse", "earthing", "ELCB"],
      },
    ],
    analogy: "Think of each answer as a chain: keyword, reason, result. If one link is missing, marks slip.",
    malayalamSupport: "Answer എഴുതുമ്പോൾ keyword ആദ്യം, കാരണം പിന്നെ, result അവസാനത്തിൽ. Flux change, induced current, P=VI എന്നിവ മറക്കരുത്.",
    manglishSupport: "Answer-il keyword first, reason next, result last. Flux change, induced current, P=VI marakkaruthu.",
  },
  visualBoard: {
    boardTitle: "EMI exam answer map",
    frames: [
      {
        id: "emi7-f1",
        title: "Induction chain",
        teacherAction: "Draw a three-box chain.",
        boardText: ["Change in magnetic flux", "Induced current", "Galvanometer deflection"],
        diagramDescription: "Three boxes connected left to right.",
        studentFocus: "Definition and experiment answers use the same chain.",
      },
      {
        id: "emi7-f2",
        title: "Generator comparison",
        teacherAction: "Make a two-column AC/DC generator table.",
        boardText: ["AC: slip rings", "DC: split rings", "Principle: electromagnetic induction"],
        diagramDescription: "Table comparing ring type and output current.",
        studentFocus: "Ring type is the scoring difference.",
      },
      {
        id: "emi7-f3",
        title: "Transmission safety line",
        teacherAction: "Write two mini chains for transmission and domestic safety.",
        boardText: ["High V -> Low I -> Low heat loss", "Excess current -> Fuse/MCB -> Circuit open"],
        diagramDescription: "Two horizontal cause-effect chains.",
        studentFocus: "Use cause-effect wording, not vague sentences.",
      },
    ],
  },
  docDoeTrick: {
    title: "K-R-R Answer Rule",
    trick: "Keyword, Reason, Result.",
    whyItWorks: "Most 2-mark and 4-mark answers in this chapter are short cause-effect chains.",
  },
  keyNotes: [
          "Important words to remember: change in magnetic field and induced current.",
          "Generators work on a simple principle: electromagnetic induction.",
          "Generators change mechanical energy to electrical energy.",
          "When we send electricity from one place to another, we use high voltage, low current, and this helps to reduce heat loss.",
          "Safety tips: be careful with excess current, use fuses/MCBs, and remember earthing and ELCB."
        ],
  formulas: [transformerFormula, powerTransmissionFormula],
  examAnswers: [
    {
      marks: 4,
      question: "Write a 4-mark answer: Why is high voltage used in long-distance power transmission?",
      answerPoints: [
        "For the same transmitted power, P = VI.",
        "When voltage is increased, current decreases.",
        "Heat loss in transmission lines decreases when current decreases.",
        "So step-up transformers are used for transmission and step-down transformers are used before domestic supply.",
      ],
      keywords: ["P = VI", "high voltage", "low current", "heat loss", "step-up", "step-down"],
      commonMistakes: ["Writing a vague answer without P = VI", "Forgetting step-down before consumers"],
      boardStyleRewrite: "For the same transmitted power, P = VI. If voltage is increased, current decreases. Since heat loss in transmission lines depends on current, low current reduces energy loss. Therefore voltage is stepped up for transmission and stepped down before domestic supply.",
    },
    {
      marks: 3,
      question: "Write a 3-mark answer on electromagnetic induction.",
      answerPoints: [
        "Electromagnetic induction is the production of induced current due to change in magnetic flux.",
        "It can be observed by moving a magnet towards or away from a coil connected to a galvanometer.",
        "The galvanometer deflects only while the magnetic flux is changing.",
      ],
      keywords: ["induced current", "change in magnetic flux", "coil", "galvanometer"],
      commonMistakes: ["Forgetting 'change'", "Not mentioning galvanometer in the experiment"],
      boardStyleRewrite: "Electromagnetic induction is the production of induced current in a conductor due to a change in magnetic flux linked with it. In the magnet-coil experiment, a galvanometer connected to the coil deflects when the magnet is moved, showing induced current.",
    },
  ],
  yourTurn: {
    prompt: "Write a 4-mark answer: Explain the working principle and parts of an AC generator.",
    expectedAnswerPoints: ["Electromagnetic induction", "armature rotates", "field magnet", "slip rings", "brushes", "AC output"],
    hint: "Use principle, parts and output.",
  },
  correctionRubric: {
    maxMarks: 4,
    scoringPoints: [
      { point: "Principle", marks: 1, requiredKeywords: ["electromagnetic induction"] },
      { point: "Flux change/rotation", marks: 1, requiredKeywords: ["rotate", "flux"] },
      { point: "Parts", marks: 1, requiredKeywords: ["field magnet", "armature"] },
      { point: "AC-specific parts/output", marks: 1, requiredKeywords: ["slip", "AC"] },
    ],
    commonMissingParts: ["slip rings", "brushes", "energy transformation"],
    feedbackTemplate: "Your answer has {covered}. Add {missing} for full marks.",
  },
  quiz: [
    {
      id: "emi7-q1",
      type: "short",
      question: "Write the keyword chain for high voltage transmission.",
      answer: "High voltage -> low current -> low heat loss",
      explanation: "This is the core 4-mark reasoning chain.",
      difficulty: "exam",
      tags: ["exam answer"],
    },
    {
      id: "emi7-q2",
      type: "mcq",
      question: "The scoring keyword pair for induction definition is",
      options: ["heat and power", "change in magnetic flux and induced current", "resistance and voltage", "earth and neutral"],
      answer: "change in magnetic flux and induced current",
      explanation: "Both are needed for a complete definition.",
      difficulty: "easy",
      tags: ["keywords"],
    },
  ],
  recap: {
    summary: [
              "Remember: K-R-R, Keyword, Reason, Result. When answering induction, generator, and transmission questions, use precise terms. Don't write vague answers like 'saves current'."
            ],
    mustRemember: ["Flux change, induced current, P = VI, slip/split rings"],
  },
  revisionSave: {
    flashcards: [
      { front: "Induction keywords?", back: "Change in magnetic flux and induced current." },
      { front: "Transmission chain?", back: "High V, low I, low heat loss." },
      { front: "AC generator ring?", back: "Slip ring." },
    ],
    revisionNotes: ["Rewrite one generator answer", "Rewrite one transmission answer"],
    weakAreaTags: ["exam answer", "keywords", "EMI revision"],
  },
  qualityFlags: { needsHumanReview: false },
});

const M8: TuitionLessonSeed = emiSeed({
  missionId: "M8",
  missionTitle: "Revision Mission - Electromagnetic Induction",
  goal: "Revise the full EMI chapter with formulas, diagrams and safety keywords.",
  estimatedMinutes: 25,
  contentType: "revision",
  tags: ["revision", "EMI", "generator", "transformer", "domestic wiring", "formula checklist"],
  sourceRefs: [EMI_SOURCE],
  sourceStatus: "source_backed",
  canTeach: true,
  pyqEvidenceStatus: "not_curated",
  recall: {
    prompt: "List any three scoring keywords from this chapter.",
    expectedPoints: ["Electromagnetic induction", "magnetic flux", "generator", "transformer", "fuse/MCB", "earthing"],
    misconceptionCheck: "Revision should not be just definitions; include diagrams, formulas and safety roles.",
  },
  teach: {
    teacherIntro: "Our big exam is coming soon, so let's make sure we understand Electromagnetic Induction really well, okay?",
    explanationBlocks: [
      {
        heading: "Concept core",
        explanation: "Changing magnetic flux produces induced current. Generator uses this to convert mechanical energy into electrical energy.",
        keyTerms: ["change in magnetic flux", "induced current", "generator"],
      },
      {
        heading: "Formula core",
        explanation: "Transformer ratio is Vs/Vp = Ns/Np. Transmission reasoning uses P = VI, so high voltage lowers current for the same power.",
        keyTerms: ["transformer ratio", "P = VI", "high voltage"],
      },
      {
        heading: "Safety core",
        explanation: "Fuse/MCB protects against excess current, earth wire protects from shock, and ELCB disconnects leakage current.",
        keyTerms: ["fuse", "MCB", "earth wire", "ELCB"],
      },
    ],
    analogy: "Revision is a switchboard: each topic has its own switch. Turn on concept, formula and safety separately.",
    malayalamSupport: "Revision-il concept, formula, safety enna moonu headings aayi padikkanam. Flux change, transformer ratio, earthing marakkaruthu.",
    manglishSupport: "Revision moonu box: concept, formula, safety. Flux change, transformer ratio, earthing keywords ready aakkanam.",
  },
  visualBoard: {
    boardTitle: "One-board EMI revision",
    frames: [
      {
        id: "emi8-f1",
        title: "Concept column",
        teacherAction: "Create a three-column board: concept, formula, safety.",
        boardText: ["Concept: flux change -> induced current", "Generator: mechanical -> electrical"],
        diagramDescription: "Left column of a revision board with induction and generator chains.",
        studentFocus: "Remember the principle chain first.",
      },
      {
        id: "emi8-f2",
        title: "Formula column",
        teacherAction: "Write transformer ratio and P = VI.",
        boardText: ["Vs/Vp = Ns/Np", "P = VI", "High V -> Low I"],
        diagramDescription: "Middle column with two formula boxes.",
        studentFocus: "Formula questions need units and substitution.",
      },
      {
        id: "emi8-f3",
        title: "Safety column",
        teacherAction: "Write fuse/MCB, earth wire and ELCB roles.",
        boardText: ["Fuse/MCB: excess current", "Earth: shock safety", "ELCB: leakage detection"],
        diagramDescription: "Right column with three domestic safety devices.",
        studentFocus: "Do not mix earth wire with neutral wire.",
      },
    ],
  },
  docDoeTrick: {
    title: "C-F-S Revision",
    trick: "Concept, Formula, Safety.",
    whyItWorks: "The chapter naturally splits into these three exam groups.",
  },
  keyNotes: [
          "Electromagnetic induction: when magnetic field changes, electricity flows.",
          "Generator: it converts car moving energy into electricity, like a car that runs on electricity.",
          "AC generator uses special wheels to help electricity flow, DC generator uses special rings.",
          "Transformer ratio: it's like a machine that changes voltage, and the ratio is like a secret code.",
          "Domestic safety: fuse is like a safety valve, MCB is like an automatic safety valve, earthing is like protecting ourselves from lightning, and ELCB is like a quick safety guard."
        ],
  formulas: [transformerFormula, powerTransmissionFormula, currentFormula],
  examAnswers: [
    {
      marks: 3,
      question: "Write three must-remember facts from Electromagnetic Induction in Daily Life.",
      answerPoints: [
        "Electromagnetic induction produces induced current due to change in magnetic flux.",
        "A generator converts mechanical energy into electrical energy.",
        "High voltage transmission reduces current and heat loss.",
      ],
      keywords: ["induced current", "magnetic flux", "generator", "high voltage", "heat loss"],
      commonMistakes: ["Writing only generator points", "Ignoring domestic wiring safety"],
      boardStyleRewrite: "Electromagnetic induction is the production of induced current due to change in magnetic flux. A generator converts mechanical energy into electrical energy using this principle. High voltage transmission reduces current and heat loss in transmission lines.",
    },
  ],
  yourTurn: {
    prompt: "Make a three-column revision table: Concept, Formula, Safety.",
    expectedAnswerPoints: ["Concept: flux change -> induced current", "Formula: Vs/Vp = Ns/Np and P = VI", "Safety: fuse/MCB, earthing, ELCB"],
    hint: "Use C-F-S.",
  },
  correctionRubric: {
    maxMarks: 3,
    scoringPoints: [
      { point: "Concept column", marks: 1, requiredKeywords: ["flux", "induced"] },
      { point: "Formula column", marks: 1, requiredKeywords: ["Vs", "P"] },
      { point: "Safety column", marks: 1, requiredKeywords: ["fuse", "earth"] },
    ],
    commonMissingParts: ["one column", "formula symbols", "safety device roles"],
    feedbackTemplate: "Your revision board has {covered}. Add {missing} before the weekend test.",
  },
  quiz: [
    {
      id: "emi8-q1",
      type: "mcq",
      question: "Which pair belongs to domestic wiring safety?",
      options: ["prism and spectrum", "fuse and earthing", "concave and convex", "amplitude and frequency"],
      answer: "fuse and earthing",
      explanation: "Fuse/MCB and earthing are domestic wiring safety topics.",
      difficulty: "easy",
      tags: ["revision"],
    },
    {
      id: "emi8-q2",
      type: "short",
      question: "Write one transformer formula used in this chapter.",
      answer: "Vs/Vp = Ns/Np",
      explanation: "Voltage ratio equals turns ratio in an ideal transformer.",
      difficulty: "medium",
      tags: ["formula revision"],
    },
  ],
  recap: {
    summary: [
              "We've revised the entire chapter with easy-to-understand concepts, formulas, and safety tips.",
              "We've covered generators, transformers, and domestic wiring, like a recipe for success.",
              "We've kept the practice questions ready, and they're like a secret ingredient to make us exam-ready!"
            ],
    mustRemember: ["C-F-S: Concept, Formula, Safety"],
  },
  revisionSave: {
    flashcards: [
      { front: "C-F-S means?", back: "Concept, Formula, Safety." },
      { front: "Generator energy change?", back: "Mechanical to electrical." },
      { front: "High voltage transmission result?", back: "Lower current and lower heat loss." },
    ],
    revisionNotes: ["Add EMI to weekend formula practice", "Revisit transformer numericals before exam answer practice"],
    weakAreaTags: ["EMI revision", "transformer formula", "domestic safety"],
  },
  qualityFlags: { needsHumanReview: false },
});

export const ELECTROMAGNETIC_INDUCTION_SEEDS: TuitionLessonSeed[] = [M1, M2, M3, M4, M5, M6, M7, M8];