2 Answers. Electric current is the movement of electric charge through a conductor. Electromagnetic waves are created by moving electric charges, but once created, they can propagate through a vacuum. Photons are the smallest packets of energy that propagate as electromagnetic waves.
Parts of the electromagnetic spectrum
A large family of waves, each with a different wavelength range is called the electromagnetic spectrum (sometimes shortened to the EM spectrum). These waves all travel at the speed of light (300,000,000 metres per second) in a vacuum.Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
The ultimate source of electromagnetic waves is moving charged particles. These travel at the speed of light and are composed of electric and magnetic
The source of all wave motion is a disturbance in matter or a vibration. Think about a water wave. Something had to displace some water for the wave
Every form of electromagnetic radiation, including visible light, oscillates in a periodic fashion with peaks and valleys, and displaying a characteristic amplitude, wavelength, and frequency that defines the direction, energy, and intensity of the radiation.
Electromagnetic waves are used to transmit long/short/FM wavelength radio waves, and TV/telephone/wireless signals or energies. They are also responsible for transmiting energy in the form of microwaves, infrared radiation (IR), visible light (VIS), ultraviolet light (UV), X-rays, and gamma rays.
Radiation from the Sun. [/caption]Radiation from the Sun, which is more popularly known as sunlight, is a mixture of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV). Actually, the Sun does not only produce IR, visible light, and UV.
Tiny electrical currents exist in the human body due to the chemical reactions that occur as part of the normal bodily functions, even in the absence of external electric fields. They cause current to flow through the body to the ground. Low-frequency magnetic fields induce circulating currents within the human body.
Electromagnetic waves don't require medium to propagate because they are formed by changing magnetic and electric field , and these fields don't require any medium to propagate . Therefore radio-waves don't require medium to propagate .
Radio waves, microwaves, visible light, and x rays are all examples of electromagnetic waves that differ from each other in wavelength. These waves are also called "electromagnetic radiation" because they radiate from the electrically charged particles.
The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.
Though the sciences generally classify EM waves into seven basic types, all are manifestations of the same phenomenon.
- Radio Waves: Instant Communication.
- Microwaves: Data and Heat.
- Infrared Waves: Invisible Heat.
- Visible Light Rays.
- Ultraviolet Waves: Energetic Light.
- X-rays: Penetrating Radiation.
- Gamma Rays: Nuclear Energy.
Scientists call them all electromagnetic radiation. The waves of energy are called electromagnetic (EM) because they have oscillating electric and magnetic fields. The photons are specific units, or packets, of energy. Sometimes those particles interact with each other and change the way the light originally behaved.
They all have things in common. In a vacuum, they all travel at the same speed - the speed of light - which is 3 × 108 m/s. They are all transverse waves, with the oscillations being electric and magnetic fields. Like all waves, they can be reflected, refracted and diffracted.
Based on the orientation of particle motion and direction of energy, there are three categories: Mechanical
waves. Electromagnetic
waves. Matter
waves.
Electromagnetic Wave
- Microwaves.
- X-ray.
- Radio waves.
- Ultraviolet waves.
In his formulation of electromagnetism, Maxwell described light as a propagating wave of electric and magnetic fields. More generally, he predicted the existence of electromagnetic radiation: coupled electric and magnetic fields traveling as waves at a speed equal to the known speed of light.
The different types of electromagnetic radiation shown in the electromagnetic spectrum consists of radio waves, microwaves, infrared waves, visible light, ultraviolet radiation, X-rays, and gamma rays. The part of the electromagnetic spectrum that we are able to see is the visible light spectrum.
