Electric currentAn electric current is a flow of charged particles, such as electrons or ions, through an electrical conductor or space. It is defined as the net rate at which electric charge flows through a surface. The moving particles are called charge carriers, which may be of several types, depending on the conductor. In electric circuits, the charge carriers are often electrons moving through a wire. In semiconductors, the charge carriers can be electrons or holes.
Alternating currentAlternating current (green curve). The horizontal axis measures time (it also represents zero voltage/current); the vertical, current or voltage.Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction.
Radio spectrumEU / NATO / US ECM ABCDEFGHIJKLMNIEEE HFVHFUHFLSCXKuKKaVWmm Other TV and radioIIIIIIIVVVIThe radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication.
Radio waveRadio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths greater than 1 millimeter (3⁄64 inch), about the diameter of a grain of rice. Radio waves with frequencies above about 1 GHz and wavelengths shorter than 30 centimeters are called microwaves.
RadioRadio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication.
Electromagnetic fieldAn electromagnetic field (also EM field) is a physical field, varying in space and time, that represents the electric and magnetic influences generated by and acting upon electric charges. The field at any point in space and time can be regarded as a combination of an electric field and a magnetic field.Magnetic fieldIn magnetism and electromagnetism, magnetic field is a physical property of space that quantifies the magnetic influence at a given location.FrequencyFrequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency.
VoltageVoltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the volt (V).OscillationOscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum and alternating current. Oscillations are often used in physics to approximate complex interactions, such as those between atoms.
HertzThe hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base units is 1/s or s−1, meaning that one hertz is one per second or the reciprocal of one second. It is used only in the case of periodic events.*As an Amazon Associate I earn from qualifying purchases.