System of units, C.G.S SYSTEM, BRITISH ENGINEERING OR F.P.S SYSTEM, M.K.S SYSTEM, SYSTEM INTERNATIONAL (S.I SYSTEM)

System of units
                The set of fundamental and derived units is called a system of units.

There are four types of system of nits.

C.G.S SYSTEM

               In this system the three                fundamental quantities length, mass and time’s units are taken as centimeter, gram and second.  In this system the force is derived quantity and its is  which is called dyne. 

No.	Fundamental Quantity	UNIT	SYMBOL
1	Length	centimeter	cm
2	Mass	gram	g
3	Time	second	s

BRITISH ENGINEERING OR F.P.S SYSTEM
                In F.P.S the length mass and time are fundamental quantities and their units are foot, pound and second respectively. 

No.	Fundamental Quantity	UNIT	SYMBOL
1	Length	foot	ft
2	Mass	pound	lb
3	Time	second	s

M.K.S SYSTEM

In M.K.S the length mass and time are fundamental quantities and their units are meter, kilogram and second respectively. In this system the force is derived quantities and its unit is  is called newton.

No.	Fundamental Quantity	UNIT	SYMBOL
1	Length	meter	m
2	Mass	kilogram	kg
3	Time	second	S

SYSTEM INTERNATIONAL (S.I SYSTEM)

                In S.I system seven quantities are taken as fundamental quantities which are also called base

quantities. Their units are called fundamental units or base units or S.I units.

These quantities are Length, mass, time, electric current, temperature, luminous intensity, amount of substances.

S.I system of units are convenient for scientific work and it is an easy way for calculation. 

There are seven Physical Quantities

No.	Fundamental Quantity	UNIT	SYMBOL
1	Length	meter	m
2	Mass	kilogram	kg
3	Time	second	s
4	Amount of substance	mole	mol
5	Thermodynamic Temperature	kelvin	K
6	Electric current	ampere	A
7	Luminous intensity	candela	Cd