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The formula for evaluating the drift velocity of charge carriers in a material of constant cross-sectional area is given by: [1] =, where u is the drift velocity of electrons, j is the current density flowing through the material, n is the charge-carrier number density, and q is the charge on the charge-carrier.
For example, the mobility of the sodium ion (Na +) in water at 25 °C is 5.19 × 10 −8 m 2 /(V·s). [1] This means that a sodium ion in an electric field of 1 V/m would have an average drift velocity of 5.19 × 10 −8 m/s. Such values can be obtained from measurements of ionic conductivity in solution.
Recall that by definition, mobility is dependent on the drift velocity. The main factor determining drift velocity (other than effective mass) is scattering time, i.e. how long the carrier is ballistically accelerated by the electric field until it scatters (collides) with something that changes its direction and/or energy. The most important ...
The drift velocity is the average velocity of the charge carriers in the drift current. The drift velocity, and resulting current, is characterized by the mobility; for details, see electron mobility (for solids) or electrical mobility (for a more general discussion). See drift–diffusion equation for the way that the drift current, diffusion ...
In direct current (DC) circuits, the streamers that form at electrodes with positive and negative voltages are different in appearance and form by different physics mechanisms. Negative streamers propagate against the direction of the electric field, that is, in the same direction as the electrons drift velocity .
In physics, the motion of an electrically charged particle such as an electron or ion in a plasma in a magnetic field can be treated as the superposition of a relatively fast circular motion around a point called the guiding center and a relatively slow drift of this point. The drift speeds may differ for various species depending on their ...
Classical mechanics is the branch of physics used to describe the motion of macroscopic objects. [1] It is the most familiar of the theories of physics. The concepts it covers, such as mass, acceleration, and force, are commonly used and known. [2] The subject is based upon a three-dimensional Euclidean space with fixed axes, called a frame of ...
The physical quantity ion mobility K is defined as the proportionality factor between an ion's drift velocity v d in a gas and an electric field of strength E. = After making the necessary adjustments to account for the n0 standard gas density, ion mobilities are often expressed as reduced mobilities.