# Table of Contents

- Page ID
- 13187

## Book: Electromagnetics I (Ellingson)

This book is intended to serve as a primary textbook for a one-semester introductory course in undergraduate engineering electromagnetics, including the following topics: electric and magnetic fields; electromagnetic properties of materials; electromagnetic waves; and devices that operate according to associated electromagnetic principles including resistors, capacitors, inductors, transformers, generators, and transmission lines.### 4: Vector Analysis

A vector is a mathematical object that has both a scalar part (i.e., a magnitude and possibly a phase), as well as a direction. Many physical quantities are best described as vectors. For example, the rate of movement through space can be described as speed; i.e., as a scalar having SI base units of m/s. However, this quantity is more completely described as velocity; i.e., as a vector whose scalar part is speed and direction indicates the direction of movement.### 5: Electrostatics

Electrostatics is the theory of the electric field in conditions in which its behavior is independent of magnetic fields, including (1) The electric field associated with fixed distributions of electric charge, (2) Capacitance (the ability of a structure to store energy in an electric field), (3) The energy associated with the electrostatic field, (4) Steady current induced in a conducting material in the presence of an electrostatic field (essentially, Ohm’s Law)### 6: Steady Current and Conductivity

Convection current consists of charged particles moving in response to mechanical forces, as opposed to being guided by the electric field. An example of a convection current is a cloud bearing free electrons that moves through the atmosphere driven by wind. Conduction current consists of charged particles moving in response to the electric field and not merely being carried by motion of the surrounding material.

### 4: The DFT as Convolution or Filtering

A major application of the FFT is fast convolution or fast filtering where the DFT of the signal is multiplied term-by-term by the DFT of the impulse (helps to be doing finite impulse response (FIR) filtering) and the time-domain output is obtained by taking the inverse DFT of that product. What is less well-known is the DFT can be calculated by convolution. There are several different approaches to this, each with different application.