Question

what is fundamental units and derived units?

Answer 1

Fundamental Units: Physical quantities which are independent and cannot be derived from other physical quantities are called fundamental quantities and their units are called the fundamental or basic units. The fundamental physical quantities are mass, time, length, temperature, electric current, intensity of light and quantity of matter.

Derived Units: The units of physical quantities which can be expressed in terms of fundamental units are called derived units. Units of speed, force, momentum etc. are derived units.

Answer 2

Mass, time, temperature, length, electric current, amount of substance, and luminous intensity are considered fundamental, but only the first three actually are.

A kilogram is the mass of a certain block of material kept in an obscure place.

A second is the amount of time for a certain number of waves of the radiaton electron of a cesium 133 at 0° Kelvin produces when jumping between the lowest level and the next one.