Take a deep breath. You have just absorbed (or at least encountered) the bulk of physics that underpins the next twenty-four chapters. A quick map of what shows up where:
| Concept from this chapter | Used to understand … |
|---|---|
| Charge, current, voltage, Ohm's law | Every circuit ever |
| Coulomb / electric field / Gauss | Capacitors, ESD, shielding, touch sensors |
| Magnetic field, Faraday | Inductors, transformers, motors, generators, wireless charging |
| Maxwell's equations | EM waves, antennas, transmission lines, RF |
| Quantum tunneling | Flash memory, transistor leakage, tunnel diodes, attacks |
| Band theory, doping, Fermi level | Diodes, transistors, every chip |
| Mobility | Transistor speed, why GaAs beats silicon for RF |
| Photons, lasers | Cameras, fiber optics, optical fault injection |
| Magnetic materials | Hard drives, transformers, motors |
| Superconductors | MRI, quantum computers, sensitive sensors |
Many of these concepts will reappear in narrower form, with practical application, in later chapters. This chapter is the soil. The next twenty-four are what grows in it.