CBSE Class 12 Physics — All 80 Board Derivations Step-by-Step with Diagrams & PYQs (Board Exam 2027)

Derivations are the most predictable marks on the CBSE Class 12 Physics paper. Section C and Section E together carry 36 marks, and roughly 25–32 of the 70 theory marks are derivation-driven — fixed steps, fixed marking scheme, learnable once. This 90-page module gives you every one of them, written the way CBSE wants them written. WHAT IS INSIDE All 80 derivations that are live in the 2026-27 board syllabus, across Units I–IX: Electrostatics, Current Electricity, Magnetism, EMI & AC, EM Waves, Optics, Dual Nature, Atoms & Nuclei and Semiconductor Electronics. Each entry carries a marks tag (2/3/5), a priority star rating, a boxed FINAL result, numbered step-by-step working, the formulae used, and a TRAP ALERT listing the exact places marking schemes cut marks — missing sign conventions, forgotten diagrams, skipped SI units. THE 2026-27 FILTER Twelve topics deleted from this year's board syllabus (potentiometer, meter bridge, cyclotron, eddy currents, hysteresis, Curie temperature, polarisation, radioactive decay law, logic gates, transistor, special-purpose diodes) are printed in a separate grey section at the back for NEET/JEE aspirants only. Nothing in the main book wastes a single minute of board revision. EXAM PRACTICE, NOT JUST THEORY Every unit ends with real CBSE Previous Year Questions (2018–2024) answered in marking-scheme style, case-based Section D questions with full solutions, and an Assertion–Reason bank with keys. A two-page Derivation Index turns the whole book into a last-week test: name in, full derivation out, from memory. HOW TO STUDY FROM IT The module opens with the order that actually works — Optics first (highest weightage, ~14 marks), then Electrostatics, Semiconductors, Atoms & Nuclei — plus the 4-minute rule: a 3-mark derivation must be writable from memory in under 4 minutes, or it isn't learned yet. For CBSE Class 12 students writing the 2027 board exam, and for school teachers who want a single derivations reference. Instant download after payment. Lifetime re-download from My Downloads.