Prerequisites/Corequisites

This course requires strong command of calculus and builds on the material covered in AP Physics C Mechanics. In college, a typical co-requisite is multivariate calculus.

Instructor and general schedule

The instructor is Dr Evangelista, Room G201, devangelista@frhsd.com

Officially, the course meets period 5 or period 6. However, due to special scheduling requirements for S&E senior projects, expect classes to be held Monday, Wednesday, and Friday during block 4 or 5. On these days, if you have period 5 or 6 it will be used for physics as scheduled. Period 7 MWF will be used for either physics or multivariate calculus with Mr Levin in G112, so that on MWF you have both physics and multivariate calculus.

Dr Evangelista also teaches AP Physics C Mechanics periods 1 and 3, and S&E Senior Projects period 7. That means he is available for extra help before school, during lunch and after school by appointment, period 2, and sometimes during period 4 (period 4 is also lab for AP Physics C Mechanics).

Electricity

Electricity deals with the presence and motion of matter posessing an electric charge. Like mass, charge is a fundamental quantity. It is extensive, conserved, and quantized. Charge can move around; it gives rise to electric fields and experiences forces when moving through magnetic fields; it takes energy to assemble a collection of charges. Unlike mass, charges can be both negative and positive, and they can both attract and repel.

Electricity is ubiquitous in modern life. Most of the devices you use on a day-to-day basis, especially including computers, smartphones, calculators, vehicles, tools, food processing/preparation/refrigeration, heating ventilation and air conditioning, lighting, etc. have electrical components within them for information storage and processing, as power systems, as sensors and actuators and displays… thus understanding the physics of electricity is a prerequisite to engineering all of these systems. Systematically developing our physical intuition and descriptions of a new type of quantity, such as electrical charge, is also instructive in learning how to think like a physicist.

Magnetism

Moving electrical charges produce magnetic fields, and magnetic fields can affect the motion of charged particles. In addition, materials exhibit magnetic behaviors as well as electrical behaviors. Magnetism is also ubiquitous in modern life, in the form of motors and other actuators, sensors, magnetic information storage devices, etc.

Electricity and magnetism together are related by a set of four equations known as Maxwell’s Equations. Solutions of these extend to descriptions of electromagnetic waves, which encompass light and the entire spectrum from radio to gamma waves. The entire body of electricity and magnetism combined form the basis of classical electrodynamics, a field of physics which provides passable and useful description of the world except where quantum effects become important.

We will definitely cover three of Maxwell’s equations in our study of AP Physics C E&M and may touch on the fourth, time permitting.

8. Electric charges, fields, and Gauss’ law

We will begin by developing the idea of an electric field by analogy with gravity and gravitational fields from point masses or from distributed masses. Electric field is a vector field that shows us where a positively test charge would want to move. Electric fields for more complex distributions of charge can be obtained from superposition and integration. In some cases, the integrals can get a little ugly, but in many cases we can sidestep directly solving these integrals through astute use of some special mathematical tricks from multivariate calculus. One example is Gauss’ law (for electrostatics). The electric field helps us understand the force on charged objects.

9. Electric potential

Electric potential deals with the energy per charge present in a field. While the electric field was a vector field, electric potential is a scalar quantity. In many cases, the potential is easier to solve for than the electric field. The two are related by some handy multivariate calculus relationships which we will also discuss. Electric potential helps us understand energy in electrical systems.

10. Conductors and capacitors

We will then build from our understanding of electric fields and potential to look at device physics applied to conductors, including real wires and resistors, and capacitors, which you may remember as devices widely used in circuits for filtering, decoupling, and energy storage. We will develop descriptions of Ohm’s Law in a material, and we will use our understanding of electric field and potential to develop lumped parameter descriptions of device behavior at a macroscopic level.

11. Electric circuits

You have already taken a first course in electronics. Here we will cover electric circuits in some detail, solving basic resistive circuits, including notions of voltage and current supplies, series and parallel resistor connections, equivalent circuits, and node methods. We will also cover simple resistor-capacitor (RC) circuits. Time permitting we will touch on resistor-inductor (RL) circuits, resistor-inductor-capacitor (RLC) circuits, DC and AC circuits, and time versus frequency domain methods. These will build on what you learned in electronics and will prepare you for more advanced circuits classes as might be encountered in a typical electrical engineering college curriculum.

12. Magnetic fields and electromagnetism

We will then move on to cover magnetic fields and find the mathematics is similar, but slightly different, to that of electric fields. We will cover some key differences between magnetic and electric fields. We will develop magnetic field descriptions of wires and collections of current carrying elements, similar to how we built up our understanding of electric fields from collections of point charges. We will also discuss different types of magnetic materials. As with our development of electric fields and how they are applied in understanding the device physics and behavior of circuit elements like resistors and capacitors, we will use what we learn to understand the physics and behavior of elements like inductors.

13. Electromagnetic induction

The final topic covered on the AP test will be electromagnetic induction, which occurs as changing magnetic fields give rise to electromotive forces (and vice versa). This is key to understanding devices such as transformers, motors and generators, moving coil loudspeakers and transducers, RFID chips, etc. The relationships between changing magnetic and electric fields is also key to understanding electromagnetic waves such as light, which we will introduce, time permitting.