CONTENTS

CONTENTS F OREWORD v P REFACE xi CHAPTER ONE E LECTRIC C HARGES AND F IELDS . Introduction . Electric Charges . Conductors and Insulators . Charging by Induction . Basic Properties of Electric Charge . Coulomb’s Law . Forces between Multiple Charges . Electric Field . Electric Field Lines . Electric Flux . Electric Dipole . Dipole in a Uniform External Field . Continuous Charge Distribution . Gauss’s Law . Application of Gauss’s Law CHAPTER TWO E LECTROSTATIC P OTENTIAL AND C APACITANCE . Introduction . Electrostatic Potential . Potential due to a Point Charge . Potential due to an Electric Dipole . Potential due to a System of Charges . Equipotential Surfaces . Potential Energy of a System of Charges . Potential Energy in an External Field . Electrostatics of Conductors . Dielectrics and Polarisation . Capacitors and Capacitance . The Parallel Plate Capacitor . Effect of Dielectric on Capacitance . Combination of Capacitors . Energy Stored in a Capacitor . Van de Graaff Generator CHAPTER THREE C URRENT E LECTRICITY . Introduction . Electric Current . Electric Currents in Conductors . Ohm’s law . Drift of Electrons and the Origin of Resistivity . Limitations of Ohm’s Law . Resistivity of various Materials . Temperature Dependence of Resistivity . Electrical Energy, Power . Combination of Resistors — Series and Parallel . Cells, emf, Internal Resistance . Cells in Series and in Parallel . Kirchhoff’s Laws . Wheatstone Bridge . Meter Bridge . Potentiometer CHAPTER FOUR M OVING C HARGES AND M AGNETISM . Introduction . Magnetic Force . Motion in a Magnetic Field . Motion in Combined Electric and Magnetic Fields . Magnetic Field due to a Current Element, Biot-Savart Law . Magnetic Field on the Axis of a Circular Current Loop . Ampere’s Circuital Law