Unit 5: The Unification of Electromagnetism

Maxwell's Equations

A set of four partial differential equations that describe electromagnetism.

Gauss’s Law for Electricity

Relates electric flux to the charge enclosed by a surface; electric field lines diverge from positive charges and converge onto negative charges.

Electric Flux

The product of the electric field and the area through which it penetrates.

Displacement Current

A term added by Maxwell to Ampère's Law, representing the changing electric flux that generates a magnetic field.

Magnetic Flux

The total magnetic field passing through a given area.

Lenz's Law

A principle that states that the induced electric current will always flow in a direction that opposes the change in magnetic flux.

Ampère-Maxwell Law

States that magnetic fields are generated by electric currents and changing electric fields.

Transverse Nature of EM Waves

The electric field, magnetic field, and direction of propagation are mutually perpendicular.

Poynting Vector

Describes the rate of energy flow per unit area in an electromagnetic wave.

Speed of Light (c)

The speed at which electromagnetic waves propagate in a vacuum, approximately 3.00 x 10^8 m/s.

Phase of EM Waves

In a vacuum, the electric and magnetic fields oscillate in phase.

Electric Field (E)

A vector field surrounding charged particles that exerts force on other charged particles.

Magnetic Field (B)

A vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials.

Gauss’s Law for Magnetism

States that the net magnetic flux through any closed surface is zero, indicating magnetic monopoles do not exist.

Orthogonal

Referring to vectors that are at right angles to one another.

Coulomb's Law

Describes the electrostatic interaction between electrically charged particles.

Electromagnetic Induction

The process by which a changing magnetic field induces an electric current.

Magnetic Monopoles

Hypothetical particles that are a single magnetic pole; their existence is not supported by current evidence.

Energy Transport in Waves

EM waves carry energy, described by the Poynting Vector, which has a direction of wave propagation.

Intensity (I) of EM Waves

The average magnitude of the Poynting vector measured in watts per square meter (W/m²).

Right-Hand Rule

A mnemonic used to determine the direction of vector products in electromagnetism.

Flux Change

A condition that leads to induced electric fields according to Faraday’s Law.

Oscillating Fields

The electric and magnetic fields in an electromagnetic wave that fluctuate in strength and direction over time.

Amplitude (E{max} or B{max})

The maximum value of the electric or magnetic field strength in an electromagnetic wave.

SI Units for Electric Field (N/C)

Newtons per Coulomb, used to quantify electric field strength.

SI Units for Magnetic Field (Tesla)

The unit of measurement for magnetic field strength.

Capacitor Charging

A process where a capacitor stores energy in the form of an electric field.

Wave Equation

A mathematical representation that describes the propagation of waves through a medium or vacuum.