CBSE Class 12 Physics Important Topics 2027
Every topic ranked by how often and how recently it was asked in 5 board + 2 official sample papers (2022–2026). Blue = board paper, green = sample paper.
Top 10 most important topics
| # | Topic | Chapter | Asked in | Importance |
|---|---|---|---|---|
| 1 | p-n junction: formation, depletion region and biasing | Semiconductor Electronics: Materials, Devices and Simple Circuits | Board 2022Board 2023Board 2025Board 2026Sample 2025Sample 2026 | ★★★★★ |
| 2 | Lorentz force / motion of charge in magnetic field | Moving Charges and Magnetism | Board 2023Board 2024Board 2025Sample 2025Sample 2026 | ★★★★★ |
| 3 | Work function, threshold, stopping potential graphs | Dual Nature of Radiation and Matter | Board 2022Board 2025Board 2026Sample 2025Sample 2026 | ★★★★★ |
| 4 | Young's double-slit experiment and interference | Wave Optics | Board 2022Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★★☆ |
| 5 | Refraction and total internal reflection | Ray Optics and Optical Instruments | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★★☆ |
| 6 | Moving coil galvanometer and its conversion (ammeter/voltmeter) | Moving Charges and Magnetism | Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| 7 | Ohm's law, drift velocity and resistivity | Current Electricity | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| 8 | Lens formula, magnification and combination of lenses | Ray Optics and Optical Instruments | Board 2022Board 2024Board 2025 | ★★★☆☆ |
| 9 | Photoelectric effect and Einstein's photoelectric equation | Dual Nature of Radiation and Matter | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| 10 | Electric flux and Gauss's law applications (wire/sheet/shell) | Electric Charges and Fields | Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
Chapter-wise important topics
Electric Charges and Fields · Electrostatics & Current Electricity
| Electric flux and Gauss's law applications (wire/sheet/shell) asked 7× | Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Coulomb's law and superposition of forces asked 3× | Board 2023Board 2025Sample 2026 | ★☆☆☆☆ |
| Electric dipole: field and torque in a uniform field asked 4× | Board 2023Board 2024Board 2026 | ★☆☆☆☆ |
| Electric field due to a point charge / system of charges asked 1× | Board 2024 | ★☆☆☆☆ |
Electrostatic Potential and Capacitance · Electrostatics & Current Electricity
| Parallel plate capacitor and effect of dielectric asked 6× | Board 2025Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
| Equipotential surfaces and relation between field and potential asked 5× | Board 2026Sample 2025 | ★★☆☆☆ |
| Potential energy of a system of charges / dipole asked 1× | Sample 2026 | ★☆☆☆☆ |
| Electric potential due to point charge / dipole / system asked 2× | Board 2023Board 2024 | ★☆☆☆☆ |
| Energy stored in a capacitor asked 1× | Board 2024 | ★☆☆☆☆ |
Current Electricity · Electrostatics & Current Electricity
| Ohm's law, drift velocity and resistivity asked 9× | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Kirchhoff's laws and circuit analysis asked 8× | Board 2023Board 2025Sample 2026 | ★★☆☆☆ |
| Combination of resistors and cells asked 4× | Board 2024Board 2025Board 2026 | ★☆☆☆☆ |
| Wheatstone bridge / metre bridge asked 3× | Board 2024Board 2026Sample 2025 | ★☆☆☆☆ |
| EMF, internal resistance and terminal voltage asked 3× | Board 2023Board 2025Sample 2026 | ★☆☆☆☆ |
| Temperature dependence of resistance asked 3× | Board 2023Board 2024Sample 2025 | ★☆☆☆☆ |
Moving Charges and Magnetism · Magnetism & Electromagnetic Induction/AC
| Lorentz force / motion of charge in magnetic field asked 12× | Board 2023Board 2024Board 2025Sample 2025Sample 2026 | ★★★★★ |
| Moving coil galvanometer and its conversion (ammeter/voltmeter) asked 9× | Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Ampere's circuital law (solenoid / toroid) asked 3× | Board 2026Sample 2025Sample 2026 | ★☆☆☆☆ |
| Torque on a current loop and magnetic dipole moment asked 4× | Board 2024Board 2025Board 2026 | ★☆☆☆☆ |
| Force between two parallel currents asked 3× | Board 2023Board 2024Sample 2026 | ★☆☆☆☆ |
| Biot-Savart law (field of straight wire / circular loop) asked 2× | Board 2023Board 2025 | ★☆☆☆☆ |
Magnetism and Matter · Magnetism & Electromagnetic Induction/AC
| Dia-, para- and ferromagnetic materials and their properties asked 4× | Board 2023Board 2026Sample 2026 | ★☆☆☆☆ |
| Magnetisation, magnetic intensity and susceptibility asked 1× | Sample 2026 | ★☆☆☆☆ |
Electromagnetic Induction · Magnetism & Electromagnetic Induction/AC
| AC generator asked 4× | Board 2023Sample 2025Sample 2026 | ★★☆☆☆ |
| Self-inductance and mutual inductance asked 5× | Board 2023Board 2024Board 2025Board 2026 | ★☆☆☆☆ |
| Faraday's laws and Lenz's law asked 2× | Board 2025 | ★☆☆☆☆ |
| Eddy currents asked 1× | Sample 2026 | ★☆☆☆☆ |
| Motional EMF asked 1× | Board 2023 | ★☆☆☆☆ |
Alternating Current · Magnetism & Electromagnetic Induction/AC
| Transformer asked 4× | Board 2024Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
| Series LCR circuit, impedance and resonance asked 5× | Board 2023Board 2024Board 2026Sample 2025 | ★★☆☆☆ |
| AC through R, L, C separately (phasors) asked 2× | Board 2024Sample 2026 | ★☆☆☆☆ |
| Power in AC circuit / power factor / wattless current asked 2× | Board 2024Board 2025 | ★☆☆☆☆ |
Electromagnetic Waves · Electromagnetic Waves & Optics
| Electromagnetic spectrum and uses of each region asked 6× | Board 2022Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
| Displacement current asked 5× | Board 2023Board 2024Board 2025Sample 2025 | ★★☆☆☆ |
| Nature and properties of electromagnetic waves asked 2× | Board 2026Sample 2026 | ★☆☆☆☆ |
Ray Optics and Optical Instruments · Electromagnetic Waves & Optics
| Refraction and total internal reflection asked 11× | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★★☆ |
| Lens formula, magnification and combination of lenses asked 12× | Board 2022Board 2024Board 2025 | ★★★☆☆ |
| Optical instruments (compound microscope / telescope) asked 8× | Board 2022Board 2023Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Refraction at a spherical surface and lens maker's formula asked 9× | Board 2022Board 2023Board 2024Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Reflection by spherical mirrors / mirror formula numericals asked 4× | Board 2023Board 2024Board 2026 | ★☆☆☆☆ |
| Refraction through a prism / dispersion asked 3× | Board 2022Board 2024Sample 2026 | ★☆☆☆☆ |
Wave Optics · Electromagnetic Waves & Optics
| Young's double-slit experiment and interference asked 12× | Board 2022Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★★☆ |
| Diffraction at a single slit asked 5× | Board 2025Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
| Huygens' principle and wavefronts asked 5× | Board 2022Board 2023Board 2025Sample 2026 | ★★☆☆☆ |
Dual Nature of Radiation and Matter · Dual Nature, Atoms & Nuclei
| Work function, threshold, stopping potential graphs asked 12× | Board 2022Board 2025Board 2026Sample 2025Sample 2026 | ★★★★★ |
| Photoelectric effect and Einstein's photoelectric equation asked 9× | Board 2023Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| de Broglie wavelength of matter waves asked 7× | Board 2022Board 2024Board 2025Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
Atoms · Dual Nature, Atoms & Nuclei
| Bohr's model and energy levels asked 8× | Board 2023Board 2024Board 2025Board 2026Sample 2026 | ★★★☆☆ |
| Rutherford's alpha-scattering / nuclear model asked 4× | Board 2022Board 2026Sample 2025Sample 2026 | ★★☆☆☆ |
| Hydrogen spectrum and spectral series asked 5× | Board 2022Board 2023Board 2024Sample 2025 | ★☆☆☆☆ |
Nuclei · Dual Nature, Atoms & Nuclei
| Mass defect and binding energy per nucleon asked 7× | Board 2023Board 2025Board 2026Sample 2025 | ★★★☆☆ |
| Nuclear size, mass-energy relation (Einstein) asked 3× | Board 2023Board 2024Sample 2026 | ★☆☆☆☆ |
| Nuclear fission and fusion asked 2× | Board 2022Sample 2026 | ★☆☆☆☆ |
Semiconductor Electronics: Materials, Devices and Simple Circuits · Electronic Devices
| p-n junction: formation, depletion region and biasing asked 13× | Board 2022Board 2023Board 2025Board 2026Sample 2025Sample 2026 | ★★★★★ |
| Junction diode as a rectifier (half-wave / full-wave) asked 9× | Board 2023Board 2024Board 2026Sample 2025Sample 2026 | ★★★☆☆ |
| Intrinsic and extrinsic semiconductors / doping / energy bands asked 7× | Board 2022Board 2023Board 2024Board 2025Sample 2025 | ★★☆☆☆ |
| Special purpose diodes (Zener, LED, photodiode, solar cell) asked 1× | Board 2022 | ★☆☆☆☆ |
Importance = how often a topic was asked × how recent, with extra weight for the latest official sample paper.