Difference between Fundamental and Derived unit
Fundamental unit
- The physical quantity which do not depends upon any other quantity for its measurement is known as fundamental quantity.
- Unit of fundamental quantities are called as fundamental unit.
- Mass, length, time etc are the quantities which do not depends upon any other quantity for measurement; hence units of these quantities are also termed as fundamental unit.
- Meter, Kilogram Second, Ampere, Candela are some oftenly used fundamental unit.
- For measurement of plane angle radian unit is used, and for measurement of solid angle steradian is taken as fundamental unit.
Derived unit
- The physical quantity which depends upon fundamental quantity for its measurement is known as derived quantity.
- Unit of derived quantities are called as derived unit.
- The units of quantities like speed can be derived as,
Speed= distance/ time
Hence the unit of speed can be given as meter/ second,
Thus ‘meter/ second’ is taken as derived unit.
- The derived quantities like velocity, work and pressure having units as meter/sec, newton-meter, newton/ meter2.