Fundamental and Derived Units F.P.S, C.G.S, M.K.S and SI Units

• F.P.S system is the British system in which the basic units of length, mass and time are foot, pound and second respectively.
• C.G.S system is the metric system in which the basic units of length, mass and time are centimeter, gram and seconds respectively.
• M.K.S system is another metric system in which the basic units of length, mass and time are metre, kilogram and second respectively
• S.I. units are referred to as Systems International units which is again of metric and the basic units, their names and symbols are as follows.

Fundamental units and derived units are the two classifications of units.

Length, mass and time are the fundamental units in all the systems (i.e) F.P.S, C.G.S, M.K.S and S.I. systems.

Example Length: What is the length of copper wire in the roll , if the roll of copper wire weighs 8kg, the dia of wire is 0.9cm and the density is 8.9 gm/cm3 ?

Solution mass of copper wire in the roll = 8kg (or)8000grams Dia of copper wire in the roll = 0.9cm Density of copper wire = 8.9 gm/cm3

Area of cross section of copper wire

Time: The S.I. unit of time, the second, is another of the base units of S.I it is defined as the time interval occupied by a number of cycles of radiation from the calcium atom. The second is the same quantity in the S.I. in the British and in the U.S. systems of units.