Henry (unit) inductor: where "V"("t") denotes the resulting voltage across the circuit, "I"("t") is the current through the circuit, and "L" is the inductance of the circuit. The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A). Expressed in combinations of SI units, the henry is: in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm (Ω). The International System of Units (SI) specifies to write the symbol of
Unit of time Most of the other units used are multiples or divisions of these three. The graphic also shows the three heavenly bodies whose orbital parameters relate to the units of time. Unit of time A unit of time or time unit is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom. The exact modern definition, from the National Institute of Standards and Technology