Units

Chapter: - 2 Units Scope: - SI units, Fundamental & Derived Units correct symbols and conventions Accuracy and errors in measurement, least count of measuring instruments and implications for errors in experimental measurements and calculations. Definitions:- Physics:- The branch of science which deals with study of natural phenomenon (facts or circumstances or occurrence observed in nature) Measurement: - The comparison of a thing with a standard. Physical Quantities: - The quantities that are measurable is called a Physical Quantity. OR Anything that can be measured is called a Physical Quantity Fundamental Physical Quantities:- A Physical quantity which does not depend on other quantity and cannot be simplified further is called a fundamental physical quantity. Ex. Length ,mass, time, temperature, etc Derived Physical Quantities: - Physical quantities that can be obtained and expressed in terms of fundamental quantities are called derived quantity. Ex. Velocity, acceleration, displacement etc Unit:- The standard used for the measurement of Physical quantities is called a Unit Fundamental Unit :- The units used in the measurement of fundamental quantities are called as Fundamental units. Ex. Metre, seconds, kilogram, degree Celsius etc