Can you explain the difference between an oscillating electric field and an oscillating magnetic field?

Oscillating Electric Field (Oscillating Electric Field) and oscillating Magnetic field (Oscillating magnetic field) are important components of electromagnetic wave, and they are interrelated and interdependent in the propagation process of electromagnetic wave. The following details the difference between oscillating electric and oscillating magnetic fields and their interactions:

Oscillating Electric Field

Definition: An oscillating electric field is an electric field that varies periodically with time and space. In electromagnetic waves, the direction and magnitude of the electric field varies with time as a sine or cosine function.

Peculiarity

• Direction: The direction of the oscillating electric field is fixed, usually perpendicular to the propagation direction of the electromagnetic wave.

• Intensity: The intensity of the oscillating electric field changes with time, and its frequency is equal to the frequency of the electromagnetic wave.

• Polarization: The polarization direction of the oscillating electric field determines the polarization characteristics of the electromagnetic wave, which can be linear polarization, circular polarization or elliptical polarization.

Effect

An oscillating electric field can exert a force on a charged particle, causing it to move or accelerate.In the process of electromagnetic wave propagation, the oscillating magnetic field will be generated by the change of oscillating electric field.

Oscillating Magnetic Field

Definition: An oscillating magnetic field is a magnetic field that changes periodically with time and space. In electromagnetic waves, the direction and magnitude of the magnetic field also change with time as a sine or cosine function.

Peculiarity

• Direction: The direction of the oscillating magnetic field is fixed, usually perpendicular to the propagation direction of the electromagnetic wave, and perpendicular to the direction of the oscillating electric field.

• Intensity: The intensity of the oscillating magnetic field changes with time, and the frequency of its change is also equal to the frequency of electromagnetic waves.

• Relationship with electric field: There is a fixed proportional relationship between the strength of the oscillating magnetic field and the strength of the oscillating electric field, that isGiven E =c given B given where c is the speed of light.

Functions

Oscillating magnetic fields can apply a force (Lorentz force) to charged particles, causing them to move or accelerate.In the process of electromagnetic wave propagation, the change of oscillating magnetic field will produce a new oscillating electric field.

Interaction between oscillating electric field and oscillating magnetic field

Propagation mechanism of electromagnetic wave

In electromagnetic waves, the oscillating electric and magnetic fields are perpendicular to each other and perpendicular to the direction of wave propagation.

The change of oscillating electric field leads to the generation of oscillating magnetic field, and the change of oscillating magnetic field leads to the generation of new oscillating electric field. This interaction allows electromagnetic waves to travel through a vacuum.

Maxwell's equations

Faraday's Law in Maxwell's equations describes how a changing electric field gives rise to a magnetic field:

 ∇×E=− ∂B/∂t

Ampere's Law with Maxwell's Addition in Maxwell's equations describes how a changing magnetic field produces an electric field:

∇×B=μ0ϵ0 ∂E/∂t

Synchronization of oscillating electric field and oscillating magnetic field

In uniform electromagnetic waves, there is a strict synchronization relationship between the oscillating electric field and the oscillating magnetic field:

Phase relationship

In electromagnetic waves, the phase difference between the oscillating electric and magnetic fields is 90∘ or π/2 radians. This means that when the electric field is at its maximum, the magnetic field is exactly zero, and vice versa.

Energy transfer

The energy of electromagnetic wave is transferred alternately between electric field and magnetic field, forming wave propagation.

Sum up

Oscillating electric field and oscillating magnetic field are two basic components of electromagnetic wave, which interact with each other during electromagnetic wave propagation, perpendicular to each other, and perpendicular to the direction of wave propagation. The change of the oscillating electric field leads to the generation of the oscillating magnetic field, and the change of the oscillating magnetic field leads to the generation of a new oscillating electric field, and this interaction enables the electromagnetic wave to propagate in the vacuum. The process can be described in detail by Maxwell equations, and there is a strict phase relationship between the oscillating electric field and the oscillating magnetic field.