SI base unit SI base unit The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived. The SI base units and their physical quantities are the meter for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance. The SI base units form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology. The names and symbols of SI base
Etymology of electricity coulombs, or should we instead use amperes, joules, or watts, or even volts? Physics texts and reference books supply no solid answer, since physicists have gradually abandoned electricity as a scientific term. And yet Quantity of Electricity still persists in its original definition in many major contemporary references. For example, in the modern SI units of physics, the SI definition of coulomb is given as both the unit quantity of electric charge and also the unit quantity of electricity. Encyclopædia Britannica defines the coulomb as the unit quantity of electricity. The Merriam-Webster dictionary, in definition 1a, defines electricity as charge.