System

SI SYSTEM

It is known as Standard International System of Units which is the improved and extended Version  of MKS SYSTEM.


SYSTEM OF UNITS


CGS SYSTEM [FRENCH System of Measurement]
Length= Centimeter (cm)
Mass   = Gram (g)
Time    = Second (s)


FPS SYSTEM [BRITISH System of Measurement]

Length= Foot 

Mass   = Pound 

Time    = Second (s)

MKS SYSTEM [METRIC System]

Length= Meter (m)

Mass   = Kilogram (kg)

Time    = Second (s)

Unit

UNIT

These are the  standard qauntites which help to carry out the measurement .eg:-meter,liter,second

Difference between fundamental and derived unit

Fundamental unit	Derived unit
The unit that do not depend upon other quantity are called fundamental unit	The units of all other physical  quantities can be expressed in terms of fundamental units are called derived units
There are independent unit.	They are dependent upon other units
Eg:- m ,kg		Eg:-m/s2,kg/m3,m3

Measurement

Measurement


MEASUREMENT 
Measurement is the comparision of a  unknown quantity with the known or the standard quantity.


PHYSICAL QUANTITY
Those quantities  which can be measured is called physical quantity.


It is divided into two types :-
a) Fundamental quantity 
Those  quantity which are independently expressed itself without the help of other  quantity are called fundamental quantity .


b) Derived quantity
Those quantity which need other quantity to express itself is called derived quantity