| {"title":"Electromagnetic Induction: A+ Guide","video_mode":"exam_focus","target_duration_range":"8-12 minutes","estimated_duration_minutes":10,"render_supported":true,"planning_only":false,"scenes":[{"scene_type":"hook","title":"Magnet & Coil = Electricity?","narration":"Imagine sliding a magnet through a coil. What happens? A current is born! This magic is called Electromagnetic Induction.","visual_direction":"Icon of a magnet moving into a coil icon, with a spark icon.","on_screen_text":"Magnet & Coil = Electricity?","duration_seconds":45,"subtitle_segments":["Discover the secret behind generators and dynamos."],"exam_tip":null,"pyq_connection":null},{"scene_type":"analogy","title":"Water Flow Analogy","narration":"Think of a wire as a pipe. A magnetic field is like water pressure. To get water flowing, you must change the pressure. Similarly, to get current, you must change the magnetic field.","visual_direction":"Card showing a water pipe with a valve, next to a wire coil with a magnet.","on_screen_text":"Water Flow Analogy","duration_seconds":60,"subtitle_segments":["Change in flux induces an EMF, just like changing pressure causes flow."],"exam_tip":null,"pyq_connection":null},{"scene_type":"meaning","title":"What is Flux?","narration":"Magnetic flux (Φ) is the total number of magnetic field lines passing through a given area. It's calculated as Φ = B.A.cosθ. For a uniform field, it's just the product of the field strength and the area perpendicular to it.","visual_direction":"Diagram of field lines passing through a loop, highlighting the area A.","on_screen_text":"What is Flux?","duration_seconds":75,"subtitle_segments":["Flux (Φ) = Magnetic Field (B) × Area (A) × cosθ."],"exam_tip":null,"pyq_connection":null},{"scene_type":"process","title":"Faraday's Law of Induction","narration":"Faraday's Law states that the induced EMF is equal to the negative rate of change of magnetic flux. The formula is ε = -dΦ/dt. The negative sign is crucial. It represents Lenz's Law, which we'll see next.","visual_direction":"Card showing the formula ε = -dΦ/dt with an arrow pointing to the negative sign.","on_screen_text":"Faraday's Law of Induction","duration_seconds":90,"subtitle_segments":["Induced EMF (ε) = - Rate of change of Flux (dΦ/dt)."],"exam_tip":null,"pyq_connection":null},{"scene_type":"keywords","title":"Key Exam Keywords","narration":"When you see a question, use these exact words: 'electromagnetic induction', 'induced EMF', 'magnetic flux', 'rate of change', 'Lenz's law'. Using these keywords correctly is how you score full marks.","visual_direction":"A checklist card with the keywords ticked off.","on_screen_text":"Key Exam Keywords","duration_seconds":60,"subtitle_segments":["Keywords: Induction, Flux, EMF, Rate of Change, Lenz's Law."],"exam_tip":null,"pyq_connection":null},{"scene_type":"exam_answer","title":"How to Write a 4-Mark Answer","narration":"For a 4-mark question on Faraday's Law, start with the definition. Then write the formula ε = -dΦ/dt. Next, explain each term: ε is induced EMF, Φ is flux, and 'd/dt' is the rate of change. Finally, state Lenz's law as the reason for the negative sign.","visual_direction":"Mockup of an exam paper with a 4-mark question and a sample answer filled in.","on_screen_text":"How to Write a 4-Mark Answer","duration_seconds":75,"subtitle_segments":["Answer Structure: Definition -> Formula -> Explanation -> Lenz's Law."],"exam_tip":null,"pyq_connection":null},{"scene_type":"common_mistake","title":"Common Mistake: Ignoring the Negative Sign","narration":"Students often forget the negative sign in ε = -dΦ/dt. This sign represents Lenz's Law. It means the induced current creates a magnetic field that opposes the original change. Forgetting it means you lose marks.","visual_direction":"A red 'X' over the formula ε = dΦ/dt, and a green '✓' over ε = -dΦ/dt.","on_screen_text":"Common Mistake: Ignoring the Negative Sign","duration_seconds":60,"subtitle_segments":["Mistake: Forgetting the negative sign = -dΦ/dt."],"exam_tip":null,"pyq_connection":null},{"scene_type":"quiz","title":"Quick Test Your Knowledge!","narration":"Question 1: What is required for electromagnetic induction? Answer: A changing magnetic flux. Question 2: What does the negative sign in Faraday's Law signify? Answer: Lenz's Law. Question 3: State Faraday's Law. Answer: The induced EMF equals the negative rate of change of magnetic flux.","visual_direction":"Quiz card with three questions and checkmark icons for answers.","on_screen_text":"Quick Test Your Knowledge!","duration_seconds":90,"subtitle_segments":["1. What is needed? 2. What does the negative sign mean? 3. State the law."],"exam_tip":null,"pyq_connection":null},{"scene_type":"recap","title":"Recap: Key Takeaways","narration":"Electromagnetic induction needs a changing magnetic flux. Faraday's Law is ε = -dΦ/dt. The negative sign is Lenz's Law, which means opposition. Remember the keywords and the 4-mark answer structure. You're ready to ace this topic!","visual_direction":"A summary card with three key points and a trophy icon.","on_screen_text":"Recap: Key Takeaways","duration_seconds":100,"subtitle_segments":["Key Takeaways: Change in Flux -> Induced EMF -> Lenz's Law."],"exam_tip":null,"pyq_connection":null}],"narration_style":"visual_tutor","visual_style":"clean_explainer","exam_focus":true,"answer_cards":[{"label":"Exam keywords","items":["Electromagnetic induction requires a changing magnetic flux.","Faraday's Law is ε = -dΦ/dt, where ε is induced EMF.","The negative sign signifies Lenz's Law: the induced current opposes the change.","Use keywords like 'flux', 'induced EMF', and 'rate of change' for full marks."]}],"quiz_moments":["What is the condition for electromagnetic induction?","Write the formula for Faraday's Law of Induction.","What is the physical significance of the negative sign in the formula?"],"revision_keywords":["Electromagnetic induction requires a changing magnetic flux.","Faraday's Law is ε = -dΦ/dt, where ε is induced EMF.","The negative sign signifies Lenz's Law: the induced current opposes the change.","Use keywords like 'flux', 'induced EMF', and 'rate of change' for full marks."],"duration_validation":{"ok":true,"errors":[],"warnings":[],"word_count":316,"scene_count":9,"total_duration_seconds":655.0,"target_seconds":600},"model_used":"sarvam:sarvam-105b","trust_note":"PYQ connection is omitted unless previous-paper data is uploaded."} |