Physics important questions for class 12th (2nd PU) Chapter wise important questions according to past 5 year question paper analysis 💯🔥 Guarented questions for 2026 boards 😎💥

 Important questions — chapterwise (Class 12 Physics, NCERT)

1. Electrostatics

• Derive the expression for the electric field on the axis of a uniformly charged ring and apply it to find field at a point. (1–2 marker reasoning + 3–5 marker derivation + 4–6 marker application).

• Calculate potential and field of a uniformly charged sphere (conductor vs non-conductor) and discuss continuity at the surface.

• Work out capacitance of (a) parallel-plate capacitor with dielectric slab partly inserted, (b) series-parallel combinations — include energy stored.

• Three charges placed at triangle vertices — find net force and potential energy; find configuration for equilibrium (stability discussion).

• Using Gauss’s law, find field for infinite plane, long wire, and spherical shell; compare results and assumptions.
• What to revise: Gauss’s law applications, potential vs field, capacitance problems (dielectric, combination, energy).

2. Current Electricity

• Derive drift velocity and relate to current density; calculate conductivity from microscopic parameters.

• Analyze complex circuits with multiple resistors and one or two cells — include internal resistance and power delivered.

• RC charging/discharging: derive time constant, charge/voltage/current expressions and solve numerical problems (including energy dissipated).

• Wheatstone bridge / meter bridge problems — find unknown resistance and sensitivity discussion.
• What to revise: RC circuits, circuit reduction, internal resistance, Kirchhoff’s laws.

3. Magnetic Effects of Current & Magnetism

• Biot-Savart: find magnetic field on axis of a current loop and at point near long straight wire; compute force between parallel wires.

• Torque on a current loop in magnetic field; magnetic dipole moment and its energy in uniform B.

• Use Ampère’s law and magnetic materials: relation between B, H, magnetization; classify dia/para/ferromagnetic responses (qualitative).

• Problems on cyclotron radius, velocity for charged particle in magnetic field.
• What to revise: Biot-Savart, Ampère, magnetic dipole moment, forces on charges/currents.

4. Electromagnetic Induction & Alternating Currents

• Faraday’s law problems: induced emf in moving loops, rotating coils; Lenz’s law sign and energy considerations.

• Self and mutual inductance — energy in inductors, RL transient circuits (derive current vs time).

• AC circuits: impedance of R, L, C; series RLC resonance (quality factor, bandwidth); power factor and average power.

• Phasor method problems — compute currents/voltages and power in circuits with given frequency.
• What to revise: Faraday’s law, L/R time constants, phasors and resonance.

5. Electromagnetic Waves

• Show that Maxwell’s equations in vacuum lead to wave equation; find speed of EM waves and relate to ε₀ & μ₀.

• Explain transverse nature, energy & Poynting vector in waves.
• What to revise: Maxwell’s correction to Ampère’s law, wave equation derivation, energy flow.

6. Optics (Ray Optics & Wave Optics)

• Derive lens maker’s formula; solve imaging problems for single lens and combination of lenses (including lateral magnification).

• Refraction through spherical surface and combination — sign conventions and numerical practice.

• Young’s double slit: fringe width, effect of changing wavelength/ slit separation/ screen distance; calculations with coherent sources.

• Thin-film interference: derive condition for constructive/destructive interference and apply to common questions.

• Diffraction: single-slit diffraction minima/maxima positions; resolving power of microscope and telescope (qualitative + numerical).
• What to revise: Lens formula, interference (Young), thin films, diffraction & resolving power.

7. Dual Nature of Matter & Radiation

• Photoelectric effect: derive stopping potential relation, dependence on intensity and frequency; calculate work function and maximum kinetic energy.

• de Broglie wavelength and its application to electrons — diffraction experiment style problems.
• What to revise: Einstein’s photoelectric equation, de Broglie relation.

8. Atoms & Nuclei

• Bohr model: derive energy levels for hydrogen-like atoms and compute spectral lines (Balmer, Lyman examples).

• Radioactivity: decay law, half-life, mean life, activity calculations, and alpha/beta decay energetics.

• Nuclear binding energy: calculate per nucleon and discuss stability; Q-value problems.
• What to revise: Bohr formula, binding energy computations, decay law.

9. Semiconductor Electronics: Materials, Devices & Simple Circuits

• Explain p-n junction diode I–V characteristics; calculate forward bias current and knee behavior qualitatively.

• Design simple amplifier using a transistor: biasing (CE), gain approximate calculation, input/output coupling.

• Logic gates: draw circuits for NAND, NOR; realize simple Boolean expressions; truth tables.
• What to revise: p-n junction behavior, transistor as amplifier/switch, basic digital logic.

10. Communication Systems

• Difference between analog and digital communication; sketch amplitude modulation (AM) and frequency modulation (FM) spectra and calculate bandwidth for given signals.

• Sampling theorem (Nyquist) statement and demonstration with numerical bandwidth problems.
• What to revise: Modulation basics, bandwidth calculations, noise basics qualitatively.

5-year trend notes (short)

• Numericals dominate: CBSE usually includes 2–3 multi-step numerical problems (electrostatics, circuits, optics, modern physics). 

• One or two long derivations (Maxwell/EM wave, lens formula, Bohr model) appear frequently in the long-answer portion. 

• RC/LC/AC resonance and power factor consistently appear in the electricity/electromagnetism section. 

• Assertion-Reason/MCQ patterns are part of Section A in recent sample papers — practice conceptual checks (reasoning-based MCQs). 

• Quick study plan for these questions (compact)

Day 1–7: Solve all Electrostatics + Current Electricity problems from list (timed).

Day 8–14: Magnetism, EM induction, AC circuits + sample problems.

Day 15–20: Optics (ray + wave) + modern physics (photoelectric, Bohr).

Day 21–24: Semiconductors, Communication and revision of difficult numericals.

Always: practice at least 5 full past papers (latest 3 years highest priority) and review marking schemes. (CBSE released sample papers/marking schemes for 2025–26 — use them for exam pattern clarity).