# CBSE CLASS 12

Unit I: Electrostaties

Chapter-1 : Electric Charges and Fields

Electric field, electric field due to a point charge, electric dipole, electric field due to a dipole, torque on a dipole in uniform electric field.

Electric field lines, Electric flux, statement of Gauss’s theorem and prove of it, 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 difference , Electric potential , electric potential due to a point charge, Electric potential due to charges of system, Electric potential of electric dipole and 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 polarisation,

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

Unit 2 : Current Electricity

Chapter 3 Current Electricity

Electric current, flow of electric charges in a metallic conductor, drift velocity, mobility and their relation with electric current, Olm’s law, electrical resistance, V-I characteristics (linear and non-linear), electrical energy and power, electrical resistivity and conductivity, Carbon resistors ( colour code for carbon resistors) series and parallel combinations of resistors, 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 laws and simple applications, Wheatstone bridge, metre bridge Potentiometer-principle and its applications to measure potential difference and for comparing EMP of two cells, measurement of internal resistance of a cell.

Unit 3 : Magnetic Effects of Current and Magnetism

Chapter 4 Moving Charges and Magnetism

Concept of magnetic field, Oersted’s experiment, Biot-Savart law and its application to determine magnetic field due to current carrying circular loop at the center and axis. Ampere’s law and its applications to infinitely long straight wire. solenoids and toroid, force on a moving charge in uniform magnetic field, Cyclotron, Force on a current-carrying conductor in a uniform magnetic field, force between two parallel current carrying conductors-definition of 1 ampere. torque experienced by a current loop in uniform magnetic field, moving coil galvanometer-its current sensitivity and conversion to ammeter and voltmeter.

chapter 5 Magnetism and Matter

Current loop as a magnetic dipole and its magnetic dipole moment, magnetic dipole moment of a revolving electron, magnetic field intensity due to a magnetic dipole (bar magnet) along its axis and perpendicular to its axis, torque on a magnetic dipole (bar magner) in a uniform magnetic field, bar magnet as an equivalent, solenoid, magnetic field lines, carth’s magnetic field and magnetic elements. Pars, dia- and ferro magnetic substances, with examples. Electromagnets and factors affecting their strengths, permanent magnets

Unit 4 : Electromagnetic Induction and Alternating Currents

Chapter 6 Electromagnetic Induction

Electromagnetic induction; Faraday’s laws, induced EMF and current, Lene’s Law, Eddy currents Self and mutual induction.

Chapter 7 Alternating Current

Alterating currents, peak and RMS value of altemating current/voltage, reactance and impedance, LC oscillations (qualitative treatment only), LCR series circuit, resonance; power in AC circuits, power factor, wattless current. AC generator and transformer

Unit 5 : Electromagnetic waves

Chapter 8 Electromagnetic Waves

Basic idea of displacement current, Electromagnetic waves, their characteristics, their Transverse nature (qualitative ideas only)

Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays) including elementary facts about their uses.
Unit 6 : Optics

Chapter 9: Ray Optics and Optical Instruments

Ray Optics: Reflection of light, spherical mirrors, mirror formula, refraction of light, total internal reflection and its applications, optical fibers, refraction at spherical surfaces, lenses, thin lens formula, lensmaker’s formula, magnification, power of a lens, combination of thin lenses in contact, refraction of light through s prism. Scattering of light blue colour of sky and reddish appearance of the sun at sunrise and sunset. Optical instruments: Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers.

Chapter 10 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, coherent sources and sustained interference of light, diffraction due to a single slit, width of central maximum, resolving power of microscope and astronomical telescope, polarisation, plane polarised light, Brewster’s law, uses of plane polarised light and Polaroids.

Unit 7: Dual Nature of Radiation and Matter

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, Davisson-Germer experiment (experimental details should be omitted; only conclusion should be explained).

Unit 8 : Atoms and Nuclei

Chapter 12 Atoms

Alpha-particle scattering experiment; Rutherford’s model of atom; Bohr model, energy levels, hydrogen spectrum

Chapter 13 : Nuclei

Composition and size of nucleus. Radioactivity, alpha, beta and gamma particles/rays and their properties: radioactive decay law, half-life and mean life, Mass-energy relation, mass defect; binding energy per nucleon and its variation with mass number, nuclear fission, nuclear fusion

Unit 9 :

Chapter 14

Electronic Devices: Semiconductor Electronics: Materials, Devices and Simple Circuits Energy bands in conductors, semiconductors and insulators (qualitative ideas only) Semiconductor diode-1-V characteristics in forward and reverse bias, diode as a rectifier, Special purpose p-n junction diodes: LED, photodiode, solar cell and Zener diode and their characteristics, zener diode as a voltage regulator