The Electromagnetic Spectrum- Introduction
The Electromagentic Spectrum, shows the various types of electromagnetic radiation, based on their wavelength. When an electric charge moves (for example, in a wire) a magnetic field is generated around the wire. Electromagnetic waves are created naturally in the uppermost atmosphere and from stars, including the Sun. Visible light, microwaves and X-rays are all examples of electromagnetic radiation. These forms of energy travel as electromagnetic waves. They may be detected using a range of different instruments.
The entire range of frequencies of electromagnetic radiation that can be generated, are called the electromagnetic spectrum. They range from low-energy radiation (radiowaves), to high-energy radiation (gamma radiation). As the energy increases, the frequency of the electromagnetic waves increase but the wavelength decreases. Electromagnetic waves all travel at the speed of light, which is 300 000 km/s.
The transfer of energy without matter is called wave motion. The number of waves produced each second, is called the frequency of the wave. This is measured in hertz (Hz); meaning cycles or waves per second. A wavelength is the distance between two successive waves, which is measured in meters. The amplitude of a wave is the maximum distance it extends beyond its middle position.
The entire range of frequencies of electromagnetic radiation that can be generated, are called the electromagnetic spectrum. They range from low-energy radiation (radiowaves), to high-energy radiation (gamma radiation). As the energy increases, the frequency of the electromagnetic waves increase but the wavelength decreases. Electromagnetic waves all travel at the speed of light, which is 300 000 km/s.
The transfer of energy without matter is called wave motion. The number of waves produced each second, is called the frequency of the wave. This is measured in hertz (Hz); meaning cycles or waves per second. A wavelength is the distance between two successive waves, which is measured in meters. The amplitude of a wave is the maximum distance it extends beyond its middle position.