CBSE Class 12 Physics

Unit-I: Electrostatics and Unit-II: Current Electricity (16 Marks)

• Chapter–1: Electric Charges and Fields: Electric charges, Conservation of charge, Coulomb's law-force between two- point charges, forces between multiple charges; superposition principle and continuous charge distribution.
• Electric field, electric field due to a point charge, electric field lines, electric dipole, electric field due to a dipole, torque on a dipole in uniform electric field.
• Electric flux, statement of Gauss's theorem and its applications to find field due to infinitely long straight wire, uniformly charged infinite plane sheet and uniformly charged thin spherical shell (field inside and outside).
• Chapter–2: Electrostatic Potential and Capacitance: Electric potential, potential difference, electric potential due to a point charge, a dipole and system of charges; equipotential surfaces, electrical potential energy of a system of two-point charges and of electric dipole in an electrostatic field.
• Conductors and insulators, free charges and bound charges inside a conductor. Dielectrics and electric polarization, capacitors and capacitance, combination of capacitors in series and in parallel, capacitance of a parallel plate capacitor with and without dielectric medium between the plates, energy stored in a capacitor (no derivation, formulae only).
• Chapter–3: Current Electricity: Electric current, flow of electric charges in a metallic conductor, drift velocity, mobility and their relation with electric current; Ohm's law, V-I characteristics (linear and non-linear), electrical energy and power, electrical resistivity and conductivity, temperature dependence of resistance, Internal resistance of a cell, potential difference and emf of a cell, combination of cells in series and in parallel, Kirchhoff's rules, Wheatstone bridge.

Note for Students: These units establish the foundation of electromagnetism by exploring stationary charges, potential energy, and the dynamics of electric current in various conductors.

Unit-III: Magnetic Effects of Current and Magnetism and Unit-IV: Electromagnetic Induction and Alternating Currents (17 Marks)

• Chapter–4: Moving Charges and Magnetism: Concept of magnetic field, Oersted's experiment. Biot - Savart law and its application to current carrying circular loop.
• Ampere's law and its applications to infinitely long straight wire. Straight solenoid (only qualitative treatment), force on a moving charge in uniform magnetic and electric fields.
• Force on a current-carrying conductor in a uniform magnetic field, force between two parallel current-carrying conductors-definition of ampere, torque experienced by a current loop in uniform magnetic field; Current loop as a magnetic dipole and its magnetic dipole moment, moving coil galvanometer- its current sensitivity and conversion to ammeter and voltmeter.
• Chapter–5: Magnetism and Matter: Bar magnet, bar magnet as an equivalent solenoid (qualitative treatment only), magnetic field intensity due to a magnetic dipole (bar magnet) along its axis and perpendicular to its axis (qualitative treatment only), torque on a magnetic dipole (bar magnet) in a uniform magnetic field (qualitative treatment only), magnetic field lines.
• Magnetic properties of materials- Para-, dia- and ferro – magnetic substances with examples, Magnetization of materials, effect of temperature on magnetic properties.
• Chapter–6: Electromagnetic Induction: Electromagnetic induction; Faraday's laws, induced EMF and current; Lenz's Law, Self and mutual induction.
• Chapter–7: Alternating Current: Alternating currents, peak and RMS value of alternating current/voltage; reactance and impedance; LCR series circuit (phasors only), resonance, power in AC circuits, power factor, wattless current. AC generator, Transformer.

Note for Students: This section bridges the gap between electricity and magnetism, detailing how moving charges create magnetic fields and how changing magnetic environments induce currents.

Unit–V: Electromagnetic Waves and Unit–VI: Optics (18 Marks)

• Chapter–8: Electromagnetic Waves: Basic idea of displacement current, Electromagnetic waves, their characteristics, their transverse nature (qualitative idea only).
• Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays) including elementary facts about their uses.
• Chapter–9: Ray Optics and Optical Instruments: Ray Optics: Reflection of light, spherical mirrors, mirror formula, refraction of light, total internal reflection and optical fibers, refraction at spherical surfaces, lenses, thin lens formula, lens maker’s formula, magnification, power of a lens, combination of thin lenses in contact, refraction of light through a prism.
• Optical instruments: Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers.
• Chapter–10: Wave Optics: Wave optics: Wave front and Huygen’s principle, reflection and refraction of plane wave at a plane surface using wave fronts. Proof of laws of reflection and refraction using Huygen’s principle.
• Interference, Young's double slit experiment and expression for fringe width (No derivation final expression only), coherent sources and sustained interference of light, diffraction due to a single slit, width of central maxima (qualitative treatment only).

Note for Students: These chapters cover the dual nature of light, exploring both its particle-like ray behavior in lenses and mirrors and its wave-like properties in interference and diffraction.

Unit–VII: Dual Nature of Radiation and Matter and Unit–VIII: Atoms and Nuclei (12 Marks)

• Chapter–11: Dual Nature of Radiation and Matter: Dual nature of radiation, Photoelectric effect, Hertz and Lenard's observations; Einstein's photoelectric equation-particle nature of light.
• Experimental study of photoelectric effect; Matter waves-wave nature of particles, de-Broglie relation.
• Chapter–12: Atoms: Alpha-particle scattering experiment; Rutherford's model of atom; Bohr model of hydrogen atom, Expression for radius of nth possible orbit, velocity and energy of electron in nth orbit, hydrogen line spectra (qualitative treatment only).
• Chapter–13: Nuclei: Composition and size of nucleus, nuclear force; Mass-energy relation, mass defect; binding energy per nucleon and its variation with mass number; nuclear fission, nuclear fusion.

Note for Students: This unit dives into modern physics, explaining the quantum behavior of light and matter alongside the internal structure of atoms and the energy within the nucleus.

Unit–IX: Electronic Devices (7 Marks)

• Chapter–14: Semiconductor Electronics: Materials, Devices and Simple Circuits: Energy bands in conductors, semiconductors and insulators (qualitative ideas only) Intrinsic and extrinsic semiconductors- p and n type, p-n junction.
• Semiconductor diode - I-V characteristics in forward and reverse bias, application of junction diode -diode as a rectifier.

Note for Students: This final unit introduces the physics of semiconductors, which is the fundamental technology behind modern electronic components like diodes and rectifiers.