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Radio Wave
Radio waves
Radio waves
are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300  GHz to as low as 3 kHz, though some definitions[1][2] describe waves above 300 MHz or 3  GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is 1 mm (0.039 in), and at 3 kHz is 100 km (62 mi). Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, communications satellites, computer networks and many other applications
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Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of VHF and higher frequencies is important for radio transmission and for radar
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Monopole Antenna
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane. The driving signal from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the lower end of the monopole and the ground plane. One side of the antenna feedline is attached to the lower end of the monopole, and the other side is attached to the ground plane, which is often the Earth. This contrasts with a dipole antenna which consists of two identical rod conductors, with the signal from the transmitter applied between the two halves of the antenna. The monopole is a resonant antenna; the rod functions as an open resonator for radio waves, oscillating with standing waves of voltage and current along its length. Therefore, the length of the antenna is determined by the wavelength of the radio waves it is used with
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Electromagnetic Interference
Electromagnetic interference
Electromagnetic interference
(EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.[1] The disturbance may degrade the performance of the circuit or even stop it from functioning. In the case of a data path, these effects can range from an increase in error rate to a total loss of the data.[2] Both man-made and natural sources generate changing electrical currents and voltages that can cause EMI: ignition systems, cellular network of mobile phones, lightning, solar flares, and auroras (Northern/Southern Lights)
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Refraction
Refraction
Refraction
is the change in direction of wave propagation due to a change in its transmission medium. The phenomenon is explained by the conservation of energy and the conservation of momentum. Owing to the change of medium, the phase velocity of the wave is changed but its frequency remains constant. This is most commonly observed when a wave passes from one medium to another at any angle other than 0° from the normal. Refraction
Refraction
of light is the most commonly observed phenomenon, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another or when water waves move into water of a different depth
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Standing Wave
In physics, a standing wave – also known as a stationary wave – is a wave in which its peaks (or any other point on the wave) do not move spatially. The amplitude of the wave at a point in space may vary with time, but its phase remains constant. The locations at which the amplitude is minimum are called nodes, and the locations where the amplitude is maximum are called antinodes. Standing waves were first noticed by Michael Faraday
Michael Faraday
in 1831
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Electric Field
An electric field is a field that surrounds electric charges. It represents charges attracting or repelling other electric charges by exerting force.[1] [2] Mathematically the electric field is a vector field that associates to each point in space the force, called the Coulomb
Coulomb
force, that would be experienced per unit of charge, by an infinitesimal test charge at that point.[3] The units of the electric field in the SI system are newtons per coulomb (N/C), or volts per meter (V/m). Electric fields are created by electric charges, and by time-varying magnetic fields. Electric fields are important in many areas of physics, and are exploited practically in electrical technology. On an atomic scale, the electric field is responsible for the attractive force between the atomic nucleus and electrons that holds atoms together, and the forces between atoms that cause chemical bonding
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KHz
The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units
International System of Units
(SI) and is defined as one cycle per second.[1] It is named for Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz
Hertz
are commonly expressed in multiples: kilohertz (103 Hz, kHz), megahertz (106 Hz, MHz), gigahertz (109 Hz, GHz), and terahertz (1012 Hz, THz). Some of the unit's most common uses are in the description of sine waves and musical tones, particularly those used in radio- and audio-related applications
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Alternating Current
Alternating current
Alternating current
(AC) is an electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction. Alternating current
Alternating current
is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations AC and DC are often used to mean simply alternating and direct, as when they modify current or voltage.[1][2] The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa
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Positive Charge
Electric charge
Electric charge
is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges; positive and negative (commonly carried by protons and electrons respectively). Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral. The SI derived unit of electric charge is the coulomb (C). In electrical engineering, it is also common to use the ampere-hour (Ah), and, in chemistry, it is common to use the elementary charge (e as a unit). The symbol Q often denotes charge
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Negative Charge
Electric charge
Electric charge
is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges; positive and negative (commonly carried by protons and electrons respectively). Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral. The SI derived unit of electric charge is the coulomb (C). In electrical engineering, it is also common to use the ampere-hour (Ah), and, in chemistry, it is common to use the elementary charge (e as a unit). The symbol Q often denotes charge
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Speed Of Light
The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its exact value is 7008299792458000000♠299,792,458 metres per second (approximately 7008300000000000000♠3.00×108 m/s, or 300,000 km/s (186,000 mi/s)[Note 3]). It is exact because the unit of length, the metre, is defined from this constant and the international standard for time.[2] According to special relativity, c is the maximum speed at which all conventional matter and hence all known forms of information in the universe can travel. Though this speed is most commonly associated with light, it is in fact the speed at which all massless particles and changes of the associated fields travel in vacuum (including electromagnetic radiation and gravitational waves). Such particles and waves travel at c regardless of the motion of the source or the inertial reference frame of the observer
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GHz
GHZ or GHz may refer to: Gigahertz
Gigahertz
(GHz), a unit of frequency Greenberger–Horne–Zeilinger state, a specific entangled quantum state of three or more particles GHZ experiment, an experiment associated with such a stateThis disambiguation page lists articles associated with the title GHZ. If
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Lightning
Lightning
Lightning
is a sudden electrostatic discharge that occurs typically during a thunderstorm. This discharge occurs between electrically charged regions of a cloud (called intra-cloud lightning or IC), between two clouds (CC lightning), or between a cloud and the ground (CG lightning). The charged regions in the atmosphere temporarily equalize themselves through this discharge referred to as a flash. A lightning flash can also be a strike if it involves an object on the ground
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Magnetic Field
A magnetic field is a force field that is created by moving electric charges (electric currents) and magnetic dipoles, and exerts a force on other nearby moving charges and magnetic dipoles. At any given point, it has a direction and a magnitude (or strength), so it is represented by a vector field. The term is used for two distinct but closely related fields denoted by the symbols B and H, where, in the International System of Units, H is measured in units of amperes per meter and B is measured in teslas or newtons per meter per ampere. H is a field introduced to account for the effects of magnetization, which is due to the presence of magnetic dipoles in materials
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James Clerk Maxwell
James Clerk Maxwell
James Clerk Maxwell
FRS FRSE (/ˈmækswɛl/;[2] 13 June 1831 – 5 November 1879) was a Scottish[3][4] scientist in the field of mathematical physics.[5] His most notable achievement was to formulate the classical theory of electromagnetic radiation, bringing together for the first time electricity, magnetism, and light as different manifestations of the same phenomenon. Maxwell's equations
Maxwell's equations
for electromagnetism have been called the "second great unification in physics"[6] after the first one realised by Isaac Newton. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light
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