Based on the general conference on weights and measures to 14th in 1971, and the results of the previous meeting, define seven basic quantities. Seventh the amount is shown in Table 2.1 and are fundamental to the International System of Units, abbreviated SI from the French “Le Systeme International d’Unites”.
Table 2.1. SI base units
derivatives unit
Derived unit is a unit derived from the basic unit. The basic unit can be combined to get more quantity measurement unit called derived unit. In addition there are two of the units without dimensions namely radian (rad) and steradian (sr), 20 units of other derivatives have a special unit names. Table 2.2 Name of derived unit derived from SI base units
In some cases, the unit of the amount of the base is less according to need, because too big or too small, for example, capacitors have basic unit is Farad, but the unit is too large, and that is often used is in μF (micro Farad) or nF (nano Farad ) even pF (pico Farad), another example is the resistors are frequently used units even kΩ to MΩ (mega Ohm) so that the required multiplying factor of the magnitude of the standard units, below is a table that provides information 2.3 the multiplier problem
Table 2.3 multiplier factor of the basic unit
