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A dipole is characterised by its dipole moment, a vector quantity shown in the figure as the blue arrow labeled M. It is the relationship between the electric field and the dipole moment that gives rise to the behaviour of the dielectric. (Note that the dipole moment points in the same direction as the electric field in the figure.
With appropriate biasing, dipole domains form and travel across the diode, allowing high frequency microwave oscillators to be built. Light-emitting diodes (LEDs) In a diode formed from a direct band-gap semiconductor, such as gallium arsenide , charge carriers that cross the junction emit photons when they recombine with the majority carrier ...
The abcoulomb (abC) is a unit of electric charge equal to 1 abA⋅s, corresponding to 10 C. The abampere (abA) or biot (Bi) is a unit of electric current, corresponding to 10 A. The abvolt (abV) is a unit of electric potential difference, corresponding to 10 nV. The abohm (abΩ) is a unit of electric resistance, corresponding to 1 nΩ.
The monopole antenna is essentially one half of the half-wave dipole, a single 1 / 4 wavelength element with the other side connected to ground or an equivalent ground plane (or counterpoise). Monopoles, which are one-half the size of a dipole, are common for long-wavelength radio signals where a dipole would be impractically large.
The electric field was formally defined as the force exerted per unit charge, but the concept of potential allows for a more useful and equivalent definition: the electric field is the local gradient of the electric potential. Usually expressed in volts per metre, the vector direction of the field is the line of greatest slope of potential, and ...
Top: The charge is at rest in frame F, so this observer sees a static electric field. An observer in another frame F ′ moves with velocity v relative to F, and sees the charge move with velocity −v with an altered electric field E due to length contraction and a magnetic field B due to the motion of the charge.
Electrical engineering can be described as all of the following: Academic discipline – branch of knowledge that is taught and researched at the college or university level. Disciplines are defined (in part), and recognized by the academic journals in which research is published, and the learned societies and academic departments or faculties ...
The X-shaped dipoles give it a wide bandwidth to cover both the VHF (174–216 MHz) and UHF (470–700 MHz) TV bands. It has a gain of 5 dB VHF and 12 dB UHF and an 18 dB front-to-back ratio. Large planar array antenna of a VHF Russian mobile air defense radar, the Nebo-M. It consists of 175 folded dipole antennas.