Id

ID
Abbreviation of Inner Diameter.
Ideal Driver
A speaker driver that delivers excellent performance in terms of polar response, power handling, efficiency, frequency range and reliability.
Ideal Gas
The particles have no internal structure, are indestructible, do not interact with each other except when they collide, and all collisions are elastic.
Ideal Gas Constant
Also known as Molar Gas Constant.
Ideal Gas Law
Gases obey the gas laws at low pressures and at temperatures above those at which they liquefy.
Ideal Solution
All molecules interact in exactly the same way; the solvent-solvent, solvent-solute, and solute-solute intermolecular forces are all equivalent.
Idempotent Law
Combining a quantity with itself either by logical addition or logical multiplication will result in a logical sum or product that is the equivalent of the quantity.
Identity
A number that when an operation is applied to a given number yields that given number. For multiplication, the identity is one and for addition the identity is zero.
Identity Law
States that any expression is equal to itself.
Idle
Internal combustion engine operating at no load and minimum engine speed.
Idler Frequency
In a parametric amplifier, the difference between the input signal and the pump signal frequency.
Idler Gear
An idler gear may be used between two gears so that the direction of rotation on the two shafts is in the same direction.