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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.
For example, the Clausius–Mossotti relation is accurate for N 2 gas up to 1000 atm between 25 °C and 125 °C. [5] Moreover, the Clausius–Mossotti relation may be applicable to substances if the applied electric field is at a sufficiently high frequencies such that any permanent dipole modes are inactive.
Continuous charge distribution. The volume charge density ρ is the amount of charge per unit volume (three dimensional), surface charge density σ is amount per unit surface area (circle) with outward unit normal nĚ‚, d is the dipole moment between two point charges, the volume density of these is the polarization density P.
A semiconductor diode, the most commonly used type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. [5] It has an exponential current–voltage characteristic. Semiconductor diodes were the first semiconductor electronic devices.
The change in P appears as a variation of surface charge density upon the crystal faces, i.e. as a variation of the electric field extending between the faces caused by a change in dipole density in the bulk. For example, a 1 cm 3 cube of quartz with 2 kN (500 lbf) of correctly applied force can produce a voltage of 12500 V. [20]
The dielectric strength of class 2 ceramic and plastic film diminishes with rising frequency. Therefore, their capacitance value decreases with increasing frequency. This phenomenon is related to the dielectric relaxation in which the time constant of the electrical dipoles is the reason for the frequency dependence of permittivity. The graph ...
The corresponding energy transfer requires or generates a voltage. A mechanical analogy in the K = 1 case with magnetic field energy (1/2)Li 2 is a body with mass M, velocity u and kinetic energy (1/2)Mu 2. The rate of change of velocity (current) multiplied with mass (inductance) requires or generates a force (an electrical voltage).
d is the thickness of the sheet or diameter of the wire (m), f is the frequency (Hz), k is a constant equal to 1 for a thin sheet and 2 for a thin wire, ρ is the resistivity of the material (Ω m), and; D is the density of the material (kg/m 3).