This book describes the classical electromagnetics, atoms in a magnetic field, spin-orbit coupling, semi-conductors, insulator-metal transition by doping, heterostructures, Landau levels, response function, quantum Hall effect, combination of g-values, half-filled Landau levels, spin-orbit interaction with 1/c coupling, flux tunnelling Goldstone mode, experimental as well as theoretical quantum Hall effect and fractional effective charge. Interpretation of the quantum Hall effect has been provided. NMR in quantum Hall effect is described and electronic polarisation at half-filled Landau levels is given. There are appendices on: Kramers time reversal, kp theory, radiation from 1-d box, effective fractional charge experiments, Bose condensation of singlet pairs at the half-filled level, plateau width and activation, elementary spin-orbit interaction, Aharonov-Bohm phase, pin-charge decoupling including Luttinger liquid, Laughlin's theory and the composite fermions.