Important Derivations for CBSE Class 12 Physics with Step-by-Step Answers
Revise important Class 12 Physics derivations chapter by chapter with a solved, downloadable and printable derivation eBook, supported by free PhysicsGurukul derivation pages and the current CBSE 2026–27 syllabus. The goal is not to memorise every equation mechanically, but to understand the physical starting point, mathematical steps, assumptions, diagram and final result.
Class 12 Physics Important Derivations eBook — ₹250
Chapterwise • Solved • PrintableThe Class 12 Physics derivation eBook provides a chapterwise collection of important selected derivations with detailed answers. It is designed for revision and self-assessment and is available as a downloadable, printable PDF.
Revise derivations alongside your regular chapter preparation.
Follow the mathematical sequence instead of memorising only the final formula.
Use digitally or print selected derivations for written revision.
Cover the solution, reproduce the derivation, then compare every step.
Class 12 Physics Derivation Roadmap — 14 Current Chapters
Use the Syllabus to Set PriorityThe current CBSE Class 12 Physics theory course contains 14 chapters. Derivation importance is not equal in every chapter, so use the notes below as a revision map rather than assuming that every chapter requires the same amount of derivation memorisation.
Strong derivation practice: Gauss’s law applications, electric dipole results
Practise potential/capacitance results; note syllabus exclusions before memorising
Drift-current relations, bridge/circuit reasoning and standard results
Biot–Savart/Ampere applications, force and galvanometer results
Current syllabus contains several qualitative-only treatments
Faraday/Lenz applications, motional emf and induction results
Reactance, impedance, resonance, power and transformer relationships
Use current syllabus scope; several ideas are qualitative
Mirror/lens/refraction and optical-instrument results
Huygens proofs are important; fringe-width expression is formula-only in current syllabus
Photoelectric and de Broglie relationships
Bohr-model expressions and related results within current syllabus
Mass-energy and binding-energy relationships
Focus on current syllabus scope; many ideas are conceptual rather than long derivations
Do Not Waste Time Learning Derivations CBSE Does Not Require
Current-Syllabus FilterA common mistake is revising an old derivation list without checking the current syllabus. The 2026–27 Physics syllabus explicitly identifies some results as formula-only or some topics as qualitative treatment. Those instructions should control your preparation.
Current syllabus: no derivation; formulae only.
Current syllabus specifies qualitative treatment.
Equivalent solenoid, dipole-field treatment and torque are marked qualitative.
Current syllabus: no derivation; final expression only.
Current syllabus specifies qualitative treatment only.
Some topics are formula-based or qualitative; use the exact syllabus wording before prioritising derivations.
Free Class 12 Physics Derivations on PhysicsGurukul
Learn the Method Before Buying More PracticePhysicsGurukul already contains detailed derivation pages for several major Class 12 chapters. Use these free pages to understand the logic and notation, then use the eBook when you want a larger organised revision collection.
Gauss’s law applications, dipole results and related derivations. → CH 2 Electrostatic Potential and Capacitance — Important Derivations
Potential, dipole and capacitance-related mathematical results. → CH 3 Current Electricity — Important Derivations
Drift-current relations and other chapterwise derivation practice. → CH 4 Moving Charges and Magnetism — Important Derivations
Biot–Savart, magnetic-force and related results. → CH 6 Electromagnetic Induction — Important Derivations
Motional emf and other induction-based derivations. → CH 7 Alternating Current — Important Derivations
AC circuits, reactance, current-voltage relations and related results. → CH 10 Wave Optics — Important Derivations
Huygens-principle proofs and chapterwise mathematical development. → DIAGRAMS Important Diagrams for Class 12 Physics
Useful visual revision alongside derivation practice. →
How to Write a Physics Derivation Step by Step
Diagram • Principle • Steps • Result • CheckA derivation is easier to remember when every mathematical line has a physical reason. Use the following structure during written practice.
Write the required quantity and the physical situation clearly.
Include only the lengths, angles, directions and quantities needed for the derivation.
For example, Gauss’s law, Faraday’s law, lens relation or conservation principle.
Do not jump from the first equation straight to the final formula when important reasoning is missing.
Symmetry, small-angle conditions, medium, sign convention or limiting assumptions should be visible.
Write the physical meaning, direction or limiting condition if it helps complete the result.
A quick unit or limiting-case check often catches missing powers, signs or constants.
True revision means reconstructing the logic, not repeatedly reading the solved answer.
A Better Way to Remember Physics Derivations
Understand → Compress → Recall → RebuildIf you know the physical reason behind the equation, the sequence is easier to reconstruct.
Starting principle → substitution → simplification → assumption → final result.
Close the solution and write the whole derivation from memory before checking.
Repeat weak derivations after 1 day, 3–4 days and again during final revision.
Check Every Derivation Against CBSE 2026–27
Syllabus • SQP • Marking SchemeThe current Physics theory paper is 70 marks and follows the 14-chapter Class 12 structure. CBSE also states that content identified by NCERT as excluded for 2026–27 will not be assessed. Keep the official curriculum and sample paper beside your derivation list during revision.
Check chapter scope, formula-only topics and qualitative-treatment instructions. → SQP Official Class XII Sample Question Paper 2026–27
Open the Physics SQP and marking scheme from CBSE Academic. →
Frequently Asked Questions
Class 12 Physics DerivationsWhat is included in the Class 12 Physics derivation eBook?
The eBook contains chapterwise important selected derivations with detailed answers for CBSE Class 12 Physics revision.
What is the price of the derivation eBook?
The current listed price is ₹250.
Can the eBook be downloaded and printed?
Yes. It is supplied as a downloadable and printable PDF after purchase.
Are all derivations in older notes still required for the 2026–27 board exam?
No. Always use the current CBSE syllabus as the deciding reference. Some topics are explicitly marked formula-only or qualitative-only, and excluded NCERT content is not to be assessed.
Is the derivation PDF editable?
No. The student eBook is a non-editable PDF. Editable teacher resources are available separately through PhysicsGurukul and EditableMaterials.
Are free derivations available on PhysicsGurukul?
Yes. Detailed free derivation pages are available for several major Class 12 Physics chapters, including Electrostatics, Current Electricity, Moving Charges and Magnetism, Electromagnetic Induction, Alternating Current and Wave Optics.
Should I memorise a derivation word for word?
No. Learn the physical setup, starting law, diagram, mathematical milestones, assumptions and final result. You should be able to reconstruct the derivation logically from a blank page.
When should I revise derivations?
Revise them chapter by chapter during the session, then reattempt weak derivations during pre-board and final board-exam revision instead of leaving all derivation practice for the end.
