EC 2253 ELECTROMAGNETIC FIELDS

EC 2253                      ELECTROMAGNETIC FIELDS                                            3 1 0 4

AIM

To familiarize the student to the concepts, calculations and pertaining to electric, magnetic and electromagnetic fields so that an in depth understanding of antennas, electronic devices, Waveguides is possible.

OBJECTIVES

• To analyze fields a potentials due to static changes
• To evaluate static magnetic fields
• To understand how materials affect electric and magnetic fields
• To understand the relation between the fields under time varying situations
• To understand principles of propagation of uniform plane waves.

UNIT I              STATIC ELECTRIC FIELDS                                                                       9

Introduction to Co-ordinate System – Rectangular – Cylindrical and Spherical Co-ordinate System – Introduction to line, Surface and Volume Integrals – Definition of Curl, Divergence and Gradient – Meaning of Stokes theorem and Divergence theorem 

Coulomb’s Law in Vector Form – Definition of Electric Field Intensity – Principle of Superposition – Electric Field due to discrete charges – Electric field due to continuous charge distribution - Electric Field due to charges distributed uniformly on an infinite and finite line – Electric Field on the axis of a uniformly charged circular disc – Electric Field due to an infinite uniformly charged sheet.

Electric Scalar Potential – Relationship between potential and electric field - Potential due to infinite uniformly charged line – Potential due to electrical dipole - Electric Flux Density – Gauss Law – Proof of Gauss Law – Applications.

UNIT II  STATIC MAGNETIC FIELD                                                                                      9

The Biot-Savart Law in vector form – Magnetic Field intensity due to a finite and infinite wire carrying a current I – Magnetic field intensity on the axis of a circular and rectangular loop carrying a current I – Ampere’s circuital law and simple applications.

Magnetic flux density – The Lorentz force equation for a moving charge and applications – Force on a wire carrying a current I placed in a magnetic field – Torque on a loop carrying a current I – Magnetic moment – Magnetic Vector Potential.

UNIT III             ELECTRIC AND MAGNETIC FIELDS IN MATERIALS                                9

Poisson’s and Laplace’s equation – Electric Polarization-Nature of dielectric materials- Definition of Capacitance – Capacitance of various geometries using Laplace’s equation – Electrostatic energy and energy density – Boundary conditions for electric fields – Electric current – Current density – point form of ohm’s law – continuity equation for current.

Definition of Inductance – Inductance of loops and solenoids – Definition of mutual inductance – simple examples. Energy density in magnetic fields – Nature of magnetic materials – magnetization and permeability - magnetic boundary conditions.

UNIT IV            TIME VARYING ELECTRIC AND MAGNETIC FIELDS                               9

Faraday’s law – Maxwell’s Second Equation in integral form from Faraday’s Law – Equation expressed in point form.

Displacement current – Ampere’s circuital law in integral form – Modified form of Ampere’s circuital law as Maxwell’s first equation in integral form – Equation expressed in point form. Maxwell’s four equations in integral form and differential form.

Poynting Vector and the flow of power – Power flow in a co-axial cable – Instantaneous Average and Complex Poynting Vector.

UNIT V ELECTROMAGNETIC WAVES                                                                   9

Derivation of Wave Equation – Uniform Plane Waves – Maxwell’s equation in Phasor form – Wave equation in Phasor form – Plane waves in free space and in a homogenous material.

Wave equation for a conducting medium – Plane waves in lossy dielectrics – Propagation in good conductors – Skin effect.

Linear, Elliptical and circular polarization – Reflection of Plane Wave from a conductor – normal incidence – Reflection of Plane Waves by a perfect dielectric – normal and oblique incidence. Dependence on Polarization.  Brewster angle.

TUTORIAL     15                                                                                                TOTAL : 60

TEXTBOOKS

1. W H.Hayt & J A Buck : “Engineering Electromagnetics” TATA McGraw-Hill, 7^th Edition 2007 (Unit I,II,III ).
2. E.C. Jordan & K.G. Balmain  “Electromagnetic Waves and Radiating Systems.” Pearson Education/PHI 4^nd edition 2006. (Unit IV, V).

REFERENCES

1.         Matthew N.O.Sadiku: “Elements of Engineering Electromagnetics” Oxford University Press, 4th edition, 2007

2.           Narayana Rao, N : “Elements of Engineering Electromagnetics” 6^th edition, Pearson Education, New Delhi, 2006.

3.         Ramo, Whinnery and Van Duzer: “Fields and Waves in Communications Electronics” John Wiley & Sons ,3^rd edition 2003.

4.         David K.Cheng: “Field and Wave Electromagnetics - Second Edition-Pearson Edition, 2004.

5.         G.S.N. Raju, Electromagnetic Field Theory & Transmission Lines, Pearson Education, 2006