SI Base and Derived Units for Electrical Engineers

The SI system of units is a modern form of the metric system. It is widely used in the electrical field throughout the world.

In this section you'll read about SI:

1. Base units
2. Derived units

Base units are the seven foundational units. Originally length, mass and time were identified as base quantities. Later on, electric current was added as the base unit so as to represent the electrical quantities. After some time units for temperature along with substance and luminous intensity were added. At present this system contains 7 quantities.

Derived units are a combination of base units which are formed by combining, multiplying or by taking powers of different numbers.

Let's define them all here:

Unit	Definition
Charge	The intrinsic property of electrons and protons
Resistance	Opposition of body against current flow
Voltage	The potential difference between two points
Current	Flow of charges from one point to another
Power	The product of current and voltage
Energy	Power per unit time
Capacitance	Ability of body to store charge
Frequency	Number of cycles covered by sine wave per second
Magnetic flux	Integral of magnetic field passing through surface