📘 NEB Class 12 Physics – Most Important Questions (2080/2081)

Chapter-wise collection of crucial short and long answer questions for NEB Class 12 Physics based on the latest curriculum and exam trends. Ideal for revision and exam preparation.

📗 Unit 1: Mechanics

🔹 Rotational Dynamics

  • Derive the expression for kinetic energy of a rotating body.

  • Define moment of inertia and radius of gyration.

  • Prove: I=MR2I = MR^2 for a circular ring.

  • Derive torque and angular momentum relation.

  • Conservation of angular momentum – statement and proof.

  • Explain rolling without slipping.

🔹 Simple Harmonic Motion (SHM)

  • What is SHM? Derive the equation a=−ω2xa = -\omega^2x.

  • Energy of a particle in SHM.

  • Period of vertical spring-mass system.

  • Damped and forced oscillations.

  • Define resonance with examples.

🔹 Fluid Mechanics

  • State and explain Archimedes’ principle.

  • Derive Bernoulli’s theorem with application.

  • Define viscosity. Derive Stoke’s law.

  • Continuity equation and its application.

  • Surface tension and angle of contact.

🌡️ Unit 2: Heat & Thermodynamics

🔹 First Law of Thermodynamics

  • Derive: ΔQ=ΔU+ΔW\Delta Q = \Delta U + \Delta W

  • Cp and Cv relation for ideal gas.

  • Work done in isothermal and adiabatic processes.

  • Adiabatic equation derivation.

🔹 Second Law & Engines

  • State Carnot’s theorem.

  • Derive efficiency of Carnot engine.

  • Compare Otto and Diesel engines.

  • Entropy: concept and formula.

🌊 Unit 3: Waves & Optics

🔹 Wave Motion

  • Transverse and longitudinal waves.

  • Equation of a progressive wave.

  • Superposition principle.

🔹 Stationary Waves & Sound

  • Harmonics in open and closed pipes.

  • Laplace’s correction.

  • Doppler effect (source and observer motion).

🔹 Interference & Diffraction

  • Young’s double-slit experiment: Derivation.

  • Conditions for constructive and destructive interference.

  • Single-slit diffraction pattern.

  • Diffraction grating and resolving power.

🔹 Polarization

  • Explain plane polarized light.

  • Brewster’s law and Malus’ law.

⚡ Unit 4: Electricity & Magnetism

🔹 Electrical Circuits

  • Kirchhoff’s laws with numerical.

  • Wheatstone bridge & meter bridge principle.

  • Potentiometer: principle and uses.

  • Conversion of galvanometer to ammeter and voltmeter.

🔹 Magnetism

  • Biot-Savart law and its application.

  • Ampere’s circuital law.

  • Force between parallel currents.

  • Magnetic field due to solenoid and toroid.

🔹 Electromagnetic Induction

  • Faraday’s laws and Lenz’s law.

  • Eddy currents and their applications.

  • Mutual and self-inductance.

  • Working of transformer.

🔹 Alternating Current (AC)

  • Define peak, rms, and average value of AC.

  • Derive current in R, L, and C circuits.

  • AC power and power factor.

  • Resonance in LCR circuit.

🔬 Unit 5: Modern Physics

🔹 Photoelectric Effect

  • Einstein’s photoelectric equation.

  • Characteristics of photoelectric effect.

  • Millikan’s oil drop experiment.

🔹 Semiconductors

  • PN junction diode: forward and reverse bias.

  • Zener diode and its application in voltage regulation.

  • Logic gates: AND, OR, NOT, NAND, NOR – truth tables.

🔹 Atomic Physics

  • Bohr’s postulates and derivation of radius and energy.

  • de Broglie hypothesis and equation.

  • X-ray properties and uses.

🔹 Nuclear Physics

  • Define half-life and mean life.

  • Derive the radioactive decay law.

  • Nuclear fission and fusion.

  • Use of radioisotopes in medicine and agriculture.

🔹 Recent Trends

  • Earthquake waves: P, S, Love, Rayleigh waves.

  • Basics of nanotechnology and its applications.

  • Introduction to gravitational waves and Higgs boson.

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