CBSE Class 12 Physics Top Derivations 2026 Explained, Exam on 20 Feb

CBSE Class 12 Physics is one of the most scoring yet concept-based subjects in the board exam. The Physics paper will be conducted from 10:30 AM to 01:30 PM on Friday, 20th February 2026. Derivations play a crucial role in securing full marks because they test conceptual clarity and presentation skills. Many 3 to 5 mark questions are directly based on standard derivations. Students who understand the logic behind formulas instead of memorising them blindly perform much better. Below is the list of the most important derivations you must revise before the exam.

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CBSE Class 12 Physics Top Derivations 2026

These derivations are repeatedly asked in CBSE board exams and are considered high scoring.
Make sure you practice writing them neatly with proper diagrams and final boxed formulas.

• Application of Gauss Law

• Electric Field due to Dipole at Axial Point

• Electric Field due to Dipole at Equatorial Point

• Torque on a Dipole in an External Field

• Electric Potential due to Dipole at Axis

• Potential Energy of Dipole in an External Field

• Capacitance of a Charged Parallel Plate Capacitor

• Capacitance when Dielectric is Filled

• Drift Velocity of Electrons

• Relation between Electric Current and Drift Velocity

• Wheatstone Bridge

• Magnetic Field Intensity due to Circular Loop at its Axis

• Magnetic Force between Two Parallel Current Carrying Wires

• Mirror Formula

• Refraction at Spherical Surface

• Lens Maker Formula

• Refraction Through Prism

• Radius of nth Orbit

• Energy in an Orbit

CBSE Class 12 Physics Top Derivations 2026 Free Explanation Video

To make revision easier, students can also watch detailed explanation videos for these derivations.

Video learning helps in understanding step-by-step logic, diagram drawing, and common mistakes to avoid in the exam. It is especially helpful for topics like Gauss Law, dipole fields, prism derivation, and Bohr model energy formula. Watching a complete derivation once and then writing it yourself improves retention significantly.

CBSE Class 12 Physics Tips

Smart revision is the key to scoring well in Physics.
Focus more on clarity of steps rather than memorising long solutions.

• Practice writing each important derivation at least twice before the exam.

• Always draw clean, labeled diagrams wherever required.

• Underline or box the final formula clearly.

• Revise previous year board questions to understand the marking scheme.

• Keep the last 15 minutes in the exam to recheck numerical substitutions and signs.