ECE 230, Winter 2020

Fields and waves

Sayak Bhattacharya
Office hour: Mon, 5-6pm (B603, R&D Block) E-mail: sayak|at|

Lectures: Mon, Fri 2:30-4:00pm (Room: A007)
Tutorials: Wed 2:30-3:30pm ((Room: A106,B105,A006))

Teaching Assistants
Yashwant Jain
Shalin Verma
Dinesh Rano
Office hours: By appointment


  • Click here to download assignment 2. Deadline is 6 p.m., April 3. Email your answer scripts to the instructor.

  • Click here to download assignment 1. New deadline is 6 p.m., March 21. Email your answer scripts to the instructor.

  • Mid-semester examination (syllabus: till lect. 10) to take place on Feb. 20, 2020 (Thurs), 10-11:30am @C21

  • Electromagnetic poster day temporarily cancelled due to COVID-19. A new date 'll be announced in due time. But keep studying your topics. [Guidelines: Form a group of 4 and select a topic related to Electromagnetics in nature or Electromagnetics in industry. The topics 'll be reviewed for technical richness before you start preparing for the poster day. All 4 members of the group needs to present and answer questions. Other faculty members 'll evaluate your performances and grade you].

  • Fri, Jan 31, 2020: No lecture (research showcase day).

  • Wed, Jan 08, 2020: tutorial to be held only in A106 (for all groups).

  • Course webpage online! The first lecture 'll be on Fri, Jan. 3, 2020.


S. No. Date Topic Advised Reading Lectures
1 Jan 3 Course outline & grading policy, Introduction & historical background
Review of vector calculus
Griff. ch 1, Sad. ch 1, 2, 3
Feyn. ch 1,2
2 Jan 6 Different coordinate systems, Line integral & conservative fields
Volume, surface integral & divergence theorem
Earnshaw's theorem & Paul trap
Griff. ch 1, Sad. ch 2, 3
Feyn. ch 2
3 Jan 10 Stoke's theorem, Dirac delta function in 3D & volume charge density of point charges
How much is divergence of a radially directed inverse square function
Coulomb's law and Gauss's law
Griff. ch 1, ch 2
Lecture note
4 Jan 13 Electrostatic potential, potential due to charge distribution, Equipotential surface, Demo starts at 44:00
Perfect conductors, Electric field and volume charge inside a perfect conductor, perfect conductors as equipotentials
Electrostatic boundary conditions Poisson's and Laplace's eq., solving Laplace's eq.
Griff. ch 2, for solution of Laplace's eq. Griff. ch 3
Lecture note
5 Jan 20 Energy of an assembly of point-charges, Electrostatic energy density, Electrostatic field inside a material
Induced dipole and dipole moment of polar molecules
Polarization vector, bound charges, Gauss's law in presence of a material medium Physical interpretation of bound surface and volume charge densities: are they real?
For the first two topics: Griff. ch 2; Griff. ch 4 for the rest
Lecture note
6 Jan 21 Surprise quiz 1 of 5

7 Jan 24 Lorentz force law, demo at 14:08 , Parallel and anti-parallel currents, demo at 15:38
Charged particles in non-uniform magnetic fields, Greatest Electromagnetic show on the earth: Aurora
Force on a current-carrying wire, surface and volume current density
More on currents: Ohm's law and eqn. of continuity
Relaxation time: conductors and insulators
Griff. ch 5
Lecture note
8 Jan 27 Biot-Savart Law,Divergence and curl of magnetic field, Ampere's law
Magnetic vector potential and its non-uniqueness
Griff. ch 5
Lecture note
9 Feb 03 Quiz 2 of 5

10 Feb 07 Boundary conditions for tangential and normal components of magnetic field
Magnetic field in matter
Magnetic dipole in a uniform magnetic field
Force on a magnetic dipole in a non-uniform magnetic field: paramagnetismDemo starts at 41:00 (liquid hanging from a magnet!)
Magnetization, Ampere's law for magnetized materials, magnetic susceptibilty and permeability
para, dia and ferromagnetic materials
Demo starts at 21:55 (You can listen to the domains in a ferromagnetic material as they flip)
Demo starts at 35:51 (Curie temperature)
Griff. ch 5 for magnetic field boundary conditions, Griff. ch 6 for the rest
Lecture note
11 Feb 10 Review of quiz 2
A glitch in Ampere's law: Introduction to Electrodynamics
Griff. 7.3.1 and 7.3.2
12 Feb 14 EMF and Faraday's law of induction
Griff. ch 7
Lecture note
13 Feb 28 Quick recap: Faraday's law of induction and Maxwell's modification to Ampere's law
Maxwell's equations: differential form, integral form, time-domain and frequency domain
Concept of complex and frequency dependent permittivity
Griff. ch 7
Lecture note
14 Mar 2 EM wave propagation: a physical picture, Polarization of EM waves, Displacement current
High frequency behavior of circuits: introduction to transmission line
Working mechanism of a transmitting antenna: Demo 1, Demo 2
Working mechanism of a receiving antenna: Demo
Potentials in Electrodynamics, Gauge freedom, Coulomb gauge and Lorentz gauge
Griff. ch 10.1
Lecture note
15 Mar 6 Dispersive medium: origin and frequency dependence of dielectric constant
Scalar wave equation
Electromagnetic wave equation, Helmholtz equation
Griff. ch 9 (Electromagnetic Waves)
Lecture note
16 Electromagnetic wave equation in 1D: uniform plane wave
Electromagnetic wave equation in 3D
Griff. ch 9
(Electromagnetic Waves)
Lecture note,
17 Poynting's theorem
Electromagnetic waves in materials: attenuation in conducting materials, skin depth
Poynting's theorem: Griff. ch 8, Griff. ch 9 for the rest
Lecture note
18, 19 Standing wave and SWR
Reflection at planar interface: normal incidence and oblique incidence
Griff. ch 9 and lecture notes
Lecture note
20 Doubt clearance session

21, 22 Transmission lines: Why KCL and KVL can't be applied at high frequencies, Electromagnetic origin of distributed transmission line parameters
Transmission line equations: voltage and current waves, propagation velocity, lossless line
Characteristic impedance and input impedance
Reflection coefficient, VSWR, Short circuit and open circuit in transmission lines
Sad. and lecture notes
Lecture note

Practice problems

Set 1 (covers till lecture 8)


Tutorial 1
Tutorial 2
Tutorial 3 and 4
Tutorial 5
Tutorial 6
Tutorial 8


  • David J. Griffiths, Introduction to Electrodynamics, Pearson 4th Ed. (2015).

  • R. Feynman, R. Leighton, M. Sands, The Feynman Lectures on Physics (Vol II)

  • Matthew. N. O. Sadiku, Elements of Electromagnetics.