### natural phenomenon | physical phenomenon | electrical phenomenon | electric potential:

Evoked potential
* are useful when it becomes necessary to test the integrity of the sensory pathway.
* is electric potential
* predict the clinical changes in a multiple sclerosis drug study.

Electric resistance
* generates heat, which melts the metal.
* is an electrical phenomenon

Electrical resistance
* depends upon the composition of the conductor and is measured in ohms.
  - due to scattering of electrons within a material
  - greater in a wire that is hot
  - units called ohms
* is the force that is in the way of the flow of current
  - opposition a conductor offers to the migration of electrons
  - ratio of the voltage applied to the electrical current it produces

Impedance
* is A. a value associated with a capacitor
  - computed as a weighted combination of distance, time, and cost factors
  - expressed in ohms
* is the degree to which an electronic component impedes the flow of current
  - measure of the resistance that a speaker puts on an amplifier
  - resistance of all the parts of a system added together
* is the resistance to current flow from amplifier in a speaker
  - the flow of alternating current
  - used in network routing and allocation

### natural phenomenon | physical phenomenon | electrical phenomenon | impedance:

Acoustic impedance
* is an intermediate property directly related to the data
  - the tendency of an object to resist being driven at a certain frequency
* ratio of pressure to flow.

### natural phenomenon | physical phenomenon | electrical phenomenon:

Inductance
* can be in phase or out of phase.
* depends entirely on the physical construction of the circuit.
  - property that is proportional to the magnetic field
  - increased by winding the coil in layers
* is the basic principle for the operation of electric generators
  - property of a coil resisting changes in current flow
  - tendency of an element to store magnetic energy
  - what opposes change in current in a circuit
* linear function by unit length.
* makes it impossible to stop current immediately.
* represents energy storage in space as a magnetic field.

Pyroelectricity
* is also a necessary consequence of ferroelectricity
* material property explored for sensor development.
+ Ceramic, Properties of ceramics, Electrical properties, Ferroelectricity and its relatives
  * In turn, pyroelectricity is seen most strongly in materials which also display the ferroelectric effect, in which a stable electric dipole can be oriented or reversed by applying an electrostatic field. Pyroelectricity is also a necessary consequence of ferroelectricity.

### natural phenomenon | physical phenomenon | electrical phenomenon:

Reactance
* arises when someone threatens our freedom of action.
* can distort the changes in voltage that signify the ones and zeros in a digital signal.
* contributes to most of the total impedance at low frequency.
* depends upon the frequency and the inductance or capacitance.
* function of frequency and relates to harmonics.
  - intense motivational state
  - different than resistance, but like resistance it is measured in ohms
  - introduced when a circuit contains an inductor or capacitor
  - variable with frequency - in capacitances inversely
* refers to the motivation to react or rebel against restriction.