This is an introductory textbook on electromagnetic fields suitable for undergraduate engineering courses in electrical engineering. It adopts a straightforward approach of presenting theoretical concepts in brief and using several worked-out examples of varied kinds to provide a further understanding of concepts. The material covered in the book broadly aims to develop formulations associated with the analysis of electrostatic, static magnetic and time-varying electromagnetic fields. A review of vector calculus, included as an appendix, provides the necessary mathematical background for understanding the treatment. The salient features of the book are:
Y Mallikarjuna Reddy, Principal, Vasireddy Venkitadri Institute of Technology, Nambur, Guntur, is a professor in the department of Electronics and Communications Engineering. He has more than 22 years of teaching experience. He obtained his MTech degree from JNTU Kakinada in 1990 and his PhD in 2009 from Osmania University, Hyderabad. He is a member of I(E) and ISTE, India. He has published research papers in journals of international repute and is currently engaged in research in the areas of radar signal and image processing.
Preface Electrostatics
Introduction to Electrostatic Fields Coulomb’s Law Force in Terms of Rectangular Coordinates Force Due to N Number of Charges Electric Field Intensity (E) Charge Distributions Electric Field Intensity Due to Charge Distributions Electric Field Due to Infinite Line Charge Electric Field Due to Finite Line Charge Electric Field Strength Due to a Circular Ring of Charge Electric Field Strength Due to an Infinite Sheet of Charge Electric Field Strength Due to a Sheet of Circular Disc Electric Field Strength at the Centre of a Half Circular Ring Electric Flux and Flux Density Electric Flux Density Due to Point Charge Q Electric Flux Density Due to Charge Distributions Gauss’ Law (Integral Form) Gauss’ Law in Point Form (Maxwell’s First Law) Divergence of Electric Flux Density Divergence Theorem of Electric Flux Density Electric Flux Density Due to Infinite Line Charge Using Gauss’ Law Flux Density Due to an Infinite Sheet Charge Using Gauss’ Law Flux Density for a Coaxial Cable Flux Density for a Spherical Shell of Charge Flux Density for a Uniformly Charged Sphere Work Done in Moving a Point Charge in an Electrostatic Field Electric Potential Potential Due to Point Charge Potential Due to N Point Charges Potential Due to Charge Distribution Potential Difference Due to an Infinite Line Charge Potential Due to a Line Charge of Finite Length Potential Due to a Circular Ring Potential Gradient Relationship between E and V: Maxwell’s Second Equation Potential Function (V) Equipotential Surfaces Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Introduction Conductors Behaviour of Conductors in an Electric Field Electric Dipole Potential Due to Electric Dipole Dipole Moment Electric Field Due to Dipole Torque on an Electric Dipole in an Electric Field Torque on a Dipole Due to the Field of Another Dipole Poisson’s and Laplace’s Equations Uniqueness Theorem Electric Field between Two Concentric Conducting Spheres Using Laplace’s Equation Electric Field of a Coaxial Cable Using Laplace’s Equation Electric Field Due to Semi Infinite Conducting Planes Electric Field Due to Two Axial Conducting Cones Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Dielectric Materials Polarization Electric Displacement Vector in Dielectrics Boundary Conditions Capacitance Capacitance between Two Concentric Spheres Capacitance of a Coaxial Cable Capacitance of Two Parallel Wires (Single-Phase Transmission Line) Energy Stored in an Electrostatic Field Energy Stored in Terms of E and D Energy Stored in a Capacitor Energy Stored in a Coaxial Cable Electric Current and Current Density Current Density Conductors and Conductivity Point Form of Ohm’s Law (Relationship between J and E Relationship between J and rv Continuity Equation Relaxation time (Tr ) Resistance and Power Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Introduction Density Additional Problems Questions Problems Answers
Multiple-Choice Questions Answers
Introduction Ampere’s Circuital Law or Ampere’s Work Law Magnetic Field Intensity Due to a Solid Conductor Magnetic Field Intensity Due to Coaxial Cable Magnetic Field Intensity Due to an Infinite Sheet of Current Magnetic Field Intensity at Any Point in between Two Infinite Parallel Surface Current Sheets Differential or Point Form of Ampere’s Circuital Law (Maxwell’s Third Equation) Stokes’ Theorem Point Form of Magnetic Flux Density Magnetic Field Intensity Due to a Solenoid Using Ampere’s Circuital Law Magnetic Field Intensity Due to a Toroid Using Ampere’s Circuital Law Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Introduction Force and Torque on a Moving Charge Force on a Differential Current Element Ampere’s Force Law: Force Between Two Current Elements Force between Two Straight Infinitely Long Parallel Conductors Magnetic Torque Due to Rectangular Loop in a Magnetic Field Magnetic Dipole and Dipole Moment Boundary Conditions for Magnetic Field Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Introduction Scalar Magnetic Potential ( Vm ) Magnetic Potential at the Centre of a Square Loop Vector Magnetic Potential ( A) The Vector Magnetic Potential for Line Current Element Poisson’s Equation for Vector Magnetic Potential Properties of Vector Magnetic Potential Vector Magnetic Potential in the Field Due to Infinite Length Conductor Vector Magnetic Potential Due to a Straight Line of Finite Length Inductor and Inductance Inductance of a Solenoid Inductance of a Toroid Inductance of a Coaxial Cable Inductance of a Two-Wire Transmission Line Mutual Inductance Neumann’s Formula for Mutual Inductance Mutual Inductance between Two Solenoids Magnetic Energy Energy Density Stored in the Magnetic Field Energy Stored Due to Mutual Inductance Magnetic Circuits Magnetic Materials Characteristics of Magnetic Materials Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Introduction Faraday’s Law Induced EMF in an AC Generator Induced EMF in a Coil Faraday’s Disc Generator Equation of Continuity for Time-Varying Fields Modified Ampere’s Circuital Law for Time-Varying Fields Displacement Current Ratio between Conduction Current Density and Displacement Current Density Differences between Conduction, Convection and Displacement Currents Differences between Displacement Current Density and Conduction Current Density Maxwell’s Equations for Static Fields Maxwell’s Equation for Sinusoidal (Harmonic) Time-Varying Fields Boundary Conditions Poynting Theorem Additional Problems Questions Problems Answers Multiple-Choice Questions Answers
Definitions Distance Vector Vector Addition Vector Multiplication Dot Product Cross Product Scalar Triple Product Vector Triple Product The Cartesian or Rectangular Coordinate System Circular Cylindrical Coordinate System Spherical Coordinate System Differential Elements Transformation of Vectors Gradient, Divergence and Curl of a Vector Vector Identities Del Operators