Electromagnetism Lecture Notes

Electric Charge

A property of matter that causes it to experience a force when placed in an electromagnetic field.

Electric Field

A field around charged particles that exerts a force on other charged particles.

Electric Flux

A measure of the electric field passing through a given area.

Electric Potential

The amount of electric potential energy per unit charge at a point in an electric field.

Gauss's Law

A law relating the electric flux through a closed surface to the charge enclosed within that surface.

Capacitors

Devices that store electrical energy in an electric field.

Conducting Materials

Materials that allow the flow of electric charge (electricity) with little resistance.

Insulating Materials

Materials that do not conduct electricity well; they inhibit the flow of electric charge.

Maxwell’s Equations

A set of four fundamental equations that describe how electric and magnetic fields interact.

Energy in Fields

The energy stored within electric and magnetic fields, relevant in many physical applications.

Scalar

A quantity that is described by a magnitude alone.

Vector

A quantity that has both magnitude and direction.

Scalar Field

A field that associates a scalar value to every point in space.

Vector Field

A field where each point in space is associated with a vector.

Electric Dipole Moment (P)

A vector quantity that represents the strength and direction of an electric dipole.

Induced Dipole

A dipole that is created when an electric field distorts the electron cloud of a neutral atom.

Electric Polarization

The phenomenon where the positive and negative charges within a material are displaced under an electric field.

Torque on a Dipole

The rotational force experienced by a dipole when placed in an electric field.

Potential Energy of a Dipole

The energy stored in a dipole due to its configuration in an electric field.

Polarizability

The measure of how susceptible a particle is to polarization by an external electric field.

Charging of Capacitors

The process of accumulating charge on the plates of a capacitor.

Discharging of Capacitors

The process of releasing stored energy from a capacitor back into the circuit.

Electric Susceptibility

A measure of how much a material will become polarized in response to an electric field.

Current Density

The electric current per unit area of cross-section.

Drift Velocity

The average velocity of charge carriers in a material due to an electric field.

Conductivity

A measure of a material's ability to conduct electric current.

Drude Model

A model that describes the behavior of electrons in metals and predicts electrical properties.

Biot-Savart Law

A fundamental law that describes the magnetic field generated by a current-carrying wire.

Magnetic Field

A field around a magnet or current that exerts a force on other magnets or currents.

Magnetic Flux

A measure of the quantity of magnetism, considering the strength and extent of a magnetic field.

Torque on Magnetic Dipole

The torque experienced by a magnetic dipole when placed in a magnetic field.

Ferromagnets

Materials that can be permanently magnetized.

Paramagnets

Materials that are weakly attracted by an external magnetic field and do not retain magnetization.

Diamagnets

Materials that create an opposing magnetic field under an external magnetic field, causing repulsion.

Magnetisation Density

The measure of the magnetic moment per unit volume of a material.

Bound Currents

Currents that arise from the alignment of magnetic dipoles in materials.

Ampere's Law

A law that relates the magnetic field around a conductor to the electric current flowing through it.

Electric Field of Symmetric Charge Distributions

The predictable electric field configuration resulting from specific geometric arrangements of charges.

Potential Energy in Electric Field

The energy associated with a charge due to its position in an electric field.

Capacitance

The ability of a system to store charge per unit voltage.

Energy Stored in a Capacitor

The energy accumulated in a capacitor, expressed as $\frac{1}{2} C V^2$, where $C$ is capacitance and $V$ is voltage.