Class 12th Physics Notes
Unit I: Electrostatics (09 marks)
- Electric Charges and Fields
- Electric charges
- Conservation of charge
- Coulomb’s law force between two-point charges
- Forces between multiple charges
- Superposition principle
- 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
- Field due to infinitely long straight wire
- Uniformly charged infinite plane sheet
- Uniformly charged thin spherical shell (field inside and outside)
- Electrostatic Potential and Capacitance
- Electric potential
- Potential difference
- Electric potential due to a point charge
- 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)
Unit II: Current Electricity (07 marks)
- 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
- Kirchhoff’s rules
- Wheatstone bridge
Unit III: Magnetic Effects of Current and Magnetism (09 marks)
- 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
- 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
Unit IV: Electromagnetic Induction and Alternating Currents (09 marks)
- Electromagnetic Induction
- Electromagnetic induction
- Faraday’s laws
- Induced EMF and current
- Lenz’s Law
- Self and mutual induction
- 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
Unit V: Electromagnetic Waves (03 marks)
- 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
Unit VI: Optics (14 marks)
- 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
- 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)
Unit VII: Dual Nature of Radiation and Matter (04 marks)
- 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
Unit VIII: Atoms and Nuclei (08 marks)
- 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)
- 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
Unit IX: Electronic Devices (07 marks)
- 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