By Dhananjayan: Electromagnetic Field Theory
Here are a few options for a social media post (for platforms like LinkedIn, Facebook, or a student forum), depending on the vibe you are going for.
4.1 Maxwell’s Equations (Differential & Integral Forms)
- Gauss’s law: ∇·D = ρ_free.
- Gauss for magnetism: ∇·B = 0.
- Faraday’s law: ∇×E = −∂B/∂t.
- Ampère–Maxwell law: ∇×H = J_free + ∂D/∂t.
5.3 Reflection & Transmission
- Plane wave at normal and oblique incidence on a planar boundary; reflection and transmission coefficients (Fresnel equations).
- Brewster angle, critical angle, total internal reflection.
- Surface waves and guided wave conditions qualitatively.
5. Diagrams and Coordinate Clarity
Every problem involving coordinate systems includes a sketched coordinate axis, showing vectors clearly. The right-hand rule is illustrated multiple times in magnetostatics. electromagnetic field theory by dhananjayan
Part 4: Time-Varying Fields – Maxwell’s Equations
This is the heart of the subject. Dhananjayan slowly builds up to Maxwell’s equations: Here are a few options for a social
- Faraday’s Law and Lenz’s Law
- Displacement current – a concept that confuses many, but is explained through conductive vs. capacitive currents
- Maxwell’s equations in integral and differential forms (point form)
- Physical significance of each equation
3.1 Steady Currents and Biot–Savart Law
- Magnetic field from steady currents: Biot–Savart integral.
- Ampère’s law (integral form) and its use in high-symmetry problems.
Part 2: Electrostatics
This section deals with electric fields at rest. Dhananjayan excels in breaking down: Gauss’s law: ∇·D = ρ_free
- Coulomb’s Law and electric field intensity (E)
- Electric flux density (D) and Gauss’s Law – with special emphasis on symmetrical charge distributions
- Electric potential (V) and potential gradient
- Boundary conditions for dielectric-dielectric and conductor-dielectric interfaces
- Capacitance calculations for parallel plate, coaxial, and spherical capacitors
Common Criticisms (Honest Review)
No book is perfect. Based on student and faculty feedback, here are some limitations:
- Less emphasis on numerical methods: Unlike Sadiku’s "Elements of Electromagnetics," this book does not introduce computational electromagnetics (FDTD, FEM).
- Antennas missing: Modern EM courses often include elementary antenna theory (dipole, arrays). Dhananjayan’s book stops at waves and transmission lines.
- Typography and errors: Some older editions had minor typographical errors in equations. The 2nd and 3rd editions have largely fixed these.
- No MATLAB/Python codes: In an era of computational simulation, the book is strictly theoretical. Students must look elsewhere for coding practice.
