MindMap Gallery electromagnetic oscillation
Mainly contains electromagnetic oscillation Electromagnetic fields and electromagnetic waves, transmission and reception of radio waves, electromagnetic spectrum, etc. I hope to be helpful!
Edited at 2024-03-12 20:28:51This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
electromagnetic waves
electromagnetic oscillation
The generation of electromagnetic oscillations
Oscillating circuit and oscillating current
Oscillation circuit
Oscillating current
The process of electromagnetic oscillation
The moment the capacitor is about to discharge
The capacitor immediately begins to discharge
Discharge completed
When the capacitor is completely discharged
Charge in reverse direction to original direction
Period and frequency of electromagnetic oscillation
Period T
The time it takes for electromagnetic oscillation to complete a periodic change
Frequency f
The number of periodic changes completed within 1 second
Electromagnetic fields and electromagnetic waves
Maxwell's theory of electromagnetic fields
A changing magnetic field produces an electric field, and a changing electric field produces a magnetic field
Maxwell's predictions about electromagnetic waves
electromagnetic waves
Electromagnetic waves are transverse waves
The wave speed of electromagnetic waves is equal to the speed of light. The essence of light is electromagnetic waves.
Features
transverse wave
Communication does not require a medium
Have wave properties
Can interfere and diffract
Electromagnetic waves have the same speed as light in a vacuum, confirming Maxwell's electromagnetic theory of light
Transmission and reception of radio waves
Emission of electromagnetic waves
To effectively emit electromagnetic waves outward, an oscillation circuit must have
High enough oscillation frequency
Use open circuit
modulation of electromagnetic waves
modulation
Make electromagnetic waves change with various signals
Classification
FM
The frequency of high-frequency electromagnetic waves changes with the strength of the signal
AM
The amplitude of high-frequency electromagnetic waves changes with the strength of the signal
reception of electromagnetic waves
Receiving principle
The conductor produces an induced current
Air conductors receive electromagnetic waves
Electrical resonance and tuning
demodulation
The process of restoring sound and image signals from high-frequency currents
The reverse process of modulation
Detection
Unlimited radio waves
Electromagnetic waves with wavelengths greater than 1mm
electromagnetic spectrum
The electromagnetic spectrum is formed by arranging the wavelengths or frequencies of various electromagnetic waves.
Sort by wavelength from longest to shortest
Unlimited radio waves
infrared
visible light
UV rays
x-ray
gamma rays
Electromagnetic waves transfer energy
Electromagnetic waves are a substance
Sun radiation
Not only visible light, but also radio waves, infrared rays, ultraviolet rays, x-rays, and gamma rays
Energy is mainly concentrated in three areas: visible light, infrared, and ultraviolet.