distinguish between primary fundamental and auxiliary fundamentals units (july 2019)

Primary fundamental units are the basic units of measurement that are used in the International System of Units (SI). These units are used to define the base quantities of length, mass, time, temperature, electric current, and luminous intensity. The primary fundamental units are:

1. Length: The meter (m) is the unit of length in the SI system.
2. Mass: The kilogram (kg) is the unit of mass in the SI system.
3. Time: The second (s) is the unit of time in the SI system.
4. Temperature: The kelvin (K) is the unit of temperature in the SI system.
5. Electric current: The ampere (A) is the unit of electric current in the SI system.
6. Luminous intensity: The candela (cd) is the unit of luminous intensity in the SI system.

Auxiliary fundamental units are derived units that are used to express quantities that cannot be expressed using the primary fundamental units alone. These units are derived by combining the primary fundamental units in various ways, and include units such as the pascal (pressure), the joule (energy), and the watt (power).

Overall, primary fundamental units are the basic units of measurement used in the SI system, while auxiliary fundamental units are derived units that are used to express quantities that cannot be expressed using the primary fundamental units alone.