Search results
Results From The WOW.Com Content Network
When the resistivity of a material has a directional component, the most general definition of resistivity must be used. It starts from the tensor-vector form of Ohm's law, which relates the electric field inside a material to the electric current flow. This equation is completely general, meaning it is valid in all cases, including those ...
The thermal conductivity of a material is a measure of its ability to conduct heat.It is commonly denoted by , , or and is measured in W·m −1 ·K −1.. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity.
The molar gas constant (also known as the gas constant, universal gas constant, or ideal gas constant) is denoted by the symbol R or R. It is the molar equivalent to the Boltzmann constant , expressed in units of energy per temperature increment per amount of substance , rather than energy per temperature increment per particle .
(Common) symbol/s Defining equation SI unit Dimension Temperature gradient: No standard symbol K⋅m −1: ΘL −1: Thermal conduction rate, thermal current, thermal/heat flux, thermal power transfer P = / W ML 2 T −3: Thermal intensity I
Electric circuit with metal and a battery U. The arrows indicate the direction of the electric field E and the electric current density j.. Qualitatively, this relationship is based upon the fact that the heat and electrical transport both involve the free electrons in the metal.
The electron mobility is defined by the equation: =. where: E is the magnitude of the electric field applied to a material,; v d is the magnitude of the electron drift velocity (in other words, the electron drift speed) caused by the electric field, and
In physics, mean free path is the average distance over which a moving particle (such as an atom, a molecule, or a photon) travels before substantially changing its direction or energy (or, in a specific context, other properties), typically as a result of one or more successive collisions with other particles.
The transistor's manufacturer will specify parameters in the datasheet called the absolute thermal resistance from junction to case (symbol: ), and the maximum allowable temperature of the semiconductor junction (symbol: ). The specification for the design should include a maximum temperature at which the circuit should function correctly.