21PHY206 ELECTRICITY AND MAGNETISM PHYSICS PAPER – III-

Unit I-

Electrostatics: Electrical pressure on a charged surface, The path traced by a charged particle in a transverse electric field, The attracted disc electrometer – construction, theory and applications, Review of concept of electric field and electric field due to point charge, Electric field due to (i) electric dipole, (ii) line of charge and (iii) charged disc A dipole in an electric field, torque on a dipole in uniform and non-uniform E fields, potential energy of an electrical dipole.

Unit II-

Electric Fields in matter: Capacitance, parallel plate capacitor, calculation of capacity of a spherical and cylindrical capacitor, energy stored in a capacitor, capacitor with dielectric, atomic view of dielectrics, polarization, electric field due to a polarised material, Gauss’s law in dielectrics, Dielectric constant, Energy density of an electrostatic field (with and without dielectric), Polarisability and susceptibility – Frequency dependence of polarisability, Clausius- Mossotti equation.

Unit III-

Magneto statics: Review of Ampere’s law, B near a long wire, Magnetic lines of induction, force between two parallel conductors, definition of ampere, B for a solenoid, Biot-savart’s law, and applications of Biot-savart’s law, The magnetic field, Lorentz force and definition of magnetic field, magnetic induction, magnetic force on a current element, circulating charges, Cyclotron resonance frequency, Cyclotron, Magnetization magnetization current density, magnetic field intensity, magnetic susceptibility and permeability.

Unit IV-

Electromagnetic Induction: Review of Faraday’s law, Faraday’s experiment, Lenz’s law, Time varying magnetic fields, Application in betatron.

Inductance: Self-inductance, LR circuit, energy in a magnetic field, magnetic energy density.

Alternating current and filter: R M S values, Response of LR, CR and LCR circuits to sinusoidal voltages (discussion using the j symbol), Series and parallel resonance, Half power frequencies, bandwidth and Q-factor, Power in electrical circuits, power factor, Maximum power transfer theorem (with proof).

Unit V-

Electromagnetic Theory And Maxwell’s Equations (12 hrs.): Displacement current, Setting up of Maxwell’s equations in SI units, Hertz experiment, Travelling electromagnetic wave, Wave equations (qualitative and quantitative) – Energy transport and Poynting vector, Poynting theorem, A radiation pressure (Normal and Oblique incidence), Concept of electric dipole, magnetic dipole, expression for energy radiated by a dipole (No derivation)