Problems In Electromagnetics Magnetic Fields Em Waves
Magnetic Fields

BiotSavart law: The magnetic field at a point is proportional to the current flowing through a wire and inversely proportional to the distance from the point to the wire.

Ampere’s law: The magnetic field around a currentcarrying wire is proportional to the current and the length of the wire.

Gauss’s law for magnetism: There are no magnetic monopoles, and the net magnetic flux through any closed surface is zero.

Magnetic dipole moment: The magnetic dipole moment of a current loop is proportional to the current and the area of the loop.

Magnetic field due to a currentcarrying wire: The magnetic field around a currentcarrying wire is in the shape of a circle, with the direction of the field given by the righthand rule.

Magnetic field due to a solenoid: The magnetic field inside a solenoid is uniform and in the direction of the solenoid’s axis.

Magnetic field due to a toroid: The magnetic field inside a toroid is uniform and in the direction of the toroid’s axis.

Faraday’s law of electromagnetic induction: A changing magnetic field induces an electric field.

Lenz’s law: The direction of the induced electric field is such that it opposes the change in magnetic flux.
EM Waves

Maxwell’s equations: A set of four partial differential equations that describe the behavior of electric and magnetic fields.

Wave equation: A partial differential equation that describes the propagation of waves.

Plane waves: EM waves that have a constant amplitude and phase across a plane perpendicular to the direction of propagation.

Spherical waves: EM waves that have a constant amplitude and phase across a sphere centered on the source.

Poynting vector: A vector that represents the energy flux of an EM wave.

Wave energy: The energy carried by an EM wave per unit time per unit area.

Wave momentum: The momentum carried by an EM wave per unit time per unit area.

Doppler effect: The change in frequency of an EM wave due to the relative motion of the source and observer.

Reflection and refraction of EM waves: The change in direction of an EM wave when it encounters a boundary between two different media.

Polarization of EM waves: The orientation of the electric field vector of an EM wave.