CBSE Class 12th Physics Exam Tips: High weightage, important formulas & more

Prafullit Srivastava and Meenakshi Tyagi The Central Board of Secondary Education (CBSE) has started the board examinations for Class 10 and 12 from February 17. After physical education, Class 12 students will brace for physics, which many students find daunting. If you are worried and want to know how to fast-track and give the final push to your preparation, here are some suggestions on important topics, formulas, high-weightage units, along with what you should do a day before exams. CBSE Board 2026 | Exam day guidelines But before that, sections C and E can be considered first, as they are with the 3 and 5-mark questions, as the brain is fresh. Use the reading time to identify the choice questions you will attempt. Don’t read the whole paper; scan for familiar territory to build confidence. > Physics is not about memorizing equations; it’s about understanding the symphony of the universe. If you can visualize the current flowing or the light bending, the math follows naturally. Physics is not about memorizing equations; it’s about understanding the symphony of the universe. If you can visualize the current flowing or the light bending, the math follows naturally. ## High weightage chapters To maximise scores, focus on these units, which traditionally carry the most weight: —Electromagnetic waves, Optics (Ray and Wave): ~18 Marks. Focus on Lens Maker’s Formula, Huygen’s principle, Young’s Double Slit Experiment (YDSE). —Electrostatics and Current Electricity: ~16 Marks. Master Gauss’s Law and Kirchhoff’s Rules. —Magnetic Effects & Alternating Current: ~17 Marks. Key focus: Moving Coil Galvanometer and LCR Circuits. —Modern Physics (Dual Nature, Atoms, Nuclei): ~12 Marks. High scoring and relatively easier to grasp. —Electronic Devices (Semiconductor Electronics): 7 marks. High scoring and relatively easier to grasp. Even if you are running short on time, never skip these topics: Current Electricity, Ray Optics, Semiconductors, Dual Nature, Atoms, Nuclei, EMI, and AC. ## Formulas to revise To solve numericals efficiently, keep these fundamental equations on your hotlist: –Gauss’s Law –Drift Velocity –Wheatstone Bridge –Lens Maker’s Formula –Einstein’s Photoelectric Equation –LCR circuit Acronyms and Mnemonics are really helpful to memorise the essential things in a short form and recollect, as the students see the question related to the same topics or area. For example: Electromagnetic Spectrum (Highest to Lowest Frequency): “Good Xylophones Use Very Interesting Music Rhythms” (Gamma, X-ray, UV, Visible, Infrared, Microwave, Radio) ELI the ICE man (for inductive circuit emf E is ahead of the current, for capacitive circuit, the current I is ahead of emf) ## Topic-wise breakdown of important chapters For students who can manage time during the revision or self-study, here is a breakdown of important topics in a chapter: Electrostatics / Current -Gauss law Application -Electric field due to a dipole -Numericals on capacitors, equivalent resistance -Drift velocity, internal resistance, potential difference and emf of cell -Meter bridge Magnetism / EMI / AC -Fleming’s rules, Faraday’s law derivation -Numerical on induced emf, AC circuits -Torque on current loop -Properties of Paramagnetic, Diamagnetic and Ferromagnetic substances. -Ray diagrams -Derivations Mirror/lens formulae and numericals -Huygen’s principle -YDSE fringe width numerical Modern Physics -Photoelectric effect graph-based questions -Numericals on de Broglie wavelength -Binding energy/mass defect Semiconductor -PN junction -Semiconductor I-V characteristics in forward and reverse bias. -Rectifier working ## How should the last day of revision look? If you are short on time, ensure you cover these specific “guaranteed” topics: –Derivations: Electric field due to a dipole, Biot-Savart Law applications, and the Mirror Formula. Graphs: Equipotential surfaces, Binding energy per nucleon, Photoelectric current vs. Intensity, and V-I characteristics of p-n junction diodes. –Devices: AC Generator, Transformer (Losses), and Astronomical Telescope (Ray diagrams) Rectifier. At the beginning of the day, you can review all derivations. Write them down once without looking. Post noon, you may go through the NCERT “Points to Ponder” and “Summary” at the end of each chapter. These are treasures for 1-mark conceptual questions. ## Things to look at while attempting questions –Even if you don’t know the full solution, write down the given values and the formula that might apply. You earn step-marks for this. –Unit Consistency: Check if all units are in SI. A common trap is mixing cm with meters. — If stuck on a theory question, draw a relevant diagram. It often triggers “muscle memory” for the associated derivation. –Definitions and laws are expected verbatim, so don’t use synonyms or equivalent statements. –Energy, force, and pressure are the terms which cannot be used interchangeably as we do in regular conversations, while answering the paper. –Writing must be scientifically accurate. Attempt numericals carefully, write the formula first, then substitution –Draw neat, labelled ray diagrams and circuit diagrams Srivastava and Tyagi are teachers of Physics at Silverline Prestige School, Ghaziabad