Physics II: E&M and Waves
Charge, field, and circuit meet light and the atom: the calculus-based second semester, from Coulomb's law to nuclear decay.
16 units · 145 topics · 678 questions
Charge as the source of it all: how two charges push and pull, how that push becomes a field, and how the field survives a whole smear of charge.
Electric Charge and Conservation of Charge · Conductors, Insulators, and Charging by Induction · Coulomb's Law · Superposition of Electric Forces · +5 more
One integral over a closed surface that turns a hopeless sum of point-charge fields into a single number, whenever you're smart about the surface you choose.
Electric Flux Through a Surface · Why Gauss's Law Always Holds · Choosing a Gaussian Surface: Spherical Symmetry · The Field Inside a Uniformly Charged Sphere · +4 more
Trading vectors for one number that remembers the work it takes to build a charge configuration, and a field you can recover from a potential's slope.
Electric Potential Energy · Electric Potential and Voltage · The Potential of a Point Charge · Potential of a Continuous Charge Distribution by Integration · +5 more
How much charge a pair of conductors can hold at a given voltage, what happens wiring several together, and how slipping in an insulator changes the answer.
Capacitors and Capacitance · The Parallel-Plate Capacitor · Capacitors in Series · Capacitors in Parallel · +3 more
What actually moves inside a wire, how slowly it moves, and how a material's own atomic jostling turns into the number you call resistance.
Electric Current · Drift Velocity and the Microscopic Model of Conduction · Resistivity and Resistance · Ohm's Law · +3 more
EMF sources, resistor networks too tangled for series or parallel shortcuts, two rules that solve them anyway, and a capacitor charging on its own exponential.
EMF and Internal Resistance · Resistors in Series · Resistors in Parallel · Kirchhoff's Junction Rule · +6 more
A field that pushes only on moving charges, bends them into circles, twists current loops, and sorts positive carriers from negative ones inside a metal strip.
What a Magnetic Field Does · The Magnetic Force on a Moving Charge · Circular Motion in a Magnetic Field · Velocity Selectors and Mass Spectrometers · +5 more
Where a magnetic field comes from: a moving charge, a whole wire built from Biot-Savart pieces, and Ampere's shortcut for symmetric currents.
The Biot-Savart Law · The Field of a Long Straight Wire · The Force Between Two Parallel Currents · The Magnetic Field of a Current Loop · +4 more
A changing magnetic flux, with no battery anywhere, driving a current that always turns out to fight the very change that created it.
Magnetic Flux · Faraday's Law · Lenz's Law · Motional EMF · +5 more
A coil that resists its own current changing, the energy it banks in its field, and what happens once that energy sloshes back and forth with a capacitor.
Mutual Inductance · Self-Inductance and Inductors · Energy Stored in a Magnetic Field · LR Circuit Transients · +2 more
Voltage and current that never sit still: resistors, capacitors, and inductors each fighting an AC source their own way, tracked with a rotating phasor arrow.
AC Sources and Sinusoidal Voltage · Resistors in AC Circuits · Capacitive Reactance · Inductive Reactance · +5 more
Four equations that finally say everything electricity and magnetism can do, and the wave they predict: light, carrying energy and momentum through empty space.
Assembling Maxwell's Equations · The Displacement Current · Plane Electromagnetic Waves · The Speed of Light from Maxwell's Equations · +4 more
Light traced as straight rays that bend at a boundary, bounce off a curve, and come together into an image you can locate with one equation, no drawing needed.
The Speed of Light and the Index of Refraction · The Law of Reflection · Images in a Plane Mirror · Snell's Law of Refraction · +10 more
What geometric optics leaves out: light interfering with itself through two slits and a thin film, bending around every edge, one photon at a time.
Huygens's Principle · Coherence and Interference · Young's Double-Slit Experiment · Double-Slit Fringe Spacing · +7 more
What has to give once every observer must measure the same speed of light: simultaneity, time, length, and the rules for adding velocities together.
The Postulates of Special Relativity · The Relativity of Simultaneity · Time Dilation · Length Contraction · +5 more
Light behaving like particles, matter behaving like waves, an atom that only glows at a few exact colors, and a nucleus trading mass for energy.
Blackbody Radiation · The Photoelectric Effect · The Compton Effect · The Bohr Model of the Hydrogen Atom · +8 more