CBSE Class 12 Physics: The 50 “Golden Topics” for Your 2026 Board Exams!

CBSE Class 12 Physics

The Complete 50 Topic Masterlist

Session 2025-26

Unit I: Electrostatics

High Probability for Case Study Questions

  1. Electric Dipole: Field at Axial and Equatorial points. Derivation
  2. Gauss’s Law: Application for Infinitely Long Wire and Thin Sheet.
  3. Equipotential Surfaces: Properties and drawings for point charges. Case Study
  4. Capacitance: Parallel Plate Capacitor with Dielectric slab:
    $$C = \frac{\epsilon_0 A}{d-t(1-1/K)}$$
  5. Energy Density: Derivation for a charged capacitor.

Unit II: Current Electricity

Focus: Kirchhoff’s Rules & Graphs

  1. Drift Velocity: Relation \(I = nAev_d\) and relaxation time.
  2. Resistivity Graphs: \(\rho\) vs Temperature for Copper and Nichrome.
  3. Internal Resistance: Relation between EMF (\(E\)) and Voltage (\(V\)).
  4. Kirchhoff’s Rules: Junction and Loop rule numericals.

Units III & IV: Magnetic Effects, EMI & AC

  1. Moving Coil Galvanometer: Principle and conversion to Voltmeter. 5 Marks
  2. Force on Charge: Path of particle in magnetic field. Case Study
  3. [Image of charged particle path in magnetic field]
  4. LCR Series Circuit: Phasor Diagram and Resonance Triangle.
  5. AC Generator: Construction and working principle.
  6. [Image of AC generator diagram]
  7. Transformer: Energy losses (Eddy currents, Hysteresis).

Unit VI: Optics (Ray & Wave)

The Highest Weightage Section

  1. Lens Maker’s Formula: Full derivation for thin lenses.
  2. Prism: Refraction and Minimum Deviation curve (\(i\) vs \(\delta\)).
  3. [Image of total internal reflection diagram]
  4. Optical Instruments: Microscope and Telescope Ray Diagrams. 5 Marks
  5. Huygens’ Principle: Reflection and Refraction Laws using Wavefronts.
  6. YDSE: Fringe width derivation and intensity distribution.

Units VII, VIII & IX: Atoms, Nuclei & Semiconductors

  1. Photoelectric Effect: Einstein’s Equation and Stopping Potential graphs.
  2. Hydrogen Spectrum: Rydberg formula and Series (Lyman to Pfund).
  3. [Image of hydrogen atom energy level diagram]
  4. Mass Defect: Binding Energy per Nucleon stability curve.
  5. PN Junction Diode: Forward and Reverse Bias VI characteristics.
  6. Full Wave Rectifier: Circuit diagram and center-tapped transformer role.

Asterisk Classes: Board Strategy

  • Case Studies: These usually come from Equipotential Surfaces, Optical Fibers (TIR), or Transformers. Read the passage twice before looking at the options.
  • Ray Diagrams: Arrows on rays are mandatory. A diagram without arrows is technically incorrect and loses 1 mark.
  • Units & SI: Always express the final answer in SI units. If the question gives distance in cm, convert to meters immediately.
© 2026 Asterisk Classes | Prepared by Balvir Singh