Question

The units of fundamental physics are called:
A. Fundamental units
B. Derived units
C. Both A and B
D. None of the above

Answer 1

Hint: These are sets of unrelated units of measurement which are defined arbitrarily and from which other units are formed or derived. These units are independent of any other unit and can neither be changed nor can be related to any other unit. They are not dependent on any other units and are used for the measurement of base quantities in physics.

Complete step-by-step answer:
We know that the range of objects and phenomena studied in physics is huge. We know that there is an incredibly short lifetime of a nucleus to the age of the Earth, from the tiny sizes of sub-nuclear particles to the vast distance to the edges of the known universe, from the force exerted by a jumping flea to the force between Earth and the Sun. If we give numerical values for physical quantities and equations for physical principles, it will allow us to understand nature much more deeply than does qualitative description alone. To comprehend these vast ranges, we must also have accepted units in which to express them. And we shall find that all physical quantities can be expressed as combinations of only four fundamental physical quantities: length, mass, time, and electric current.
We should know that there are two major systems of units used in the world: SI units (also known as the metric system) and English units (also known as the customary or imperial system). English units were historically used in nations once ruled by the British Empire and are still widely used in the United States. Virtually every other country in the world now uses SI units as the standard; the metric system is also the standard system agreed upon by scientists and mathematicians.
We should know that the International System of Units (SI) consists of 7 fundamental units and all the units derived from them.
The seven basic units are:
Meter [m] = length, defined by the speed of light.
Kilogram [kg] = weight, defined by the Kilogram Prototype in Paris, will be redefined with fundamental constants of nature sooner or later.
Second [s] = time, defined by the physical properties of a certain kind of Cesium atom (Cs-133).
Ampere [A] = electric current, defined by the force between two hypothetical electric conductors.
Kelvin [K] = temperature, defined by the thermodynamic properties of water (the triple point specifically).
Mole [mol] = amount of substance, defined by the number of atoms contained by 12 grams of a certain type of Carbon (C-12).
Candela [cd] = luminous intensity, defined by a certain type of radiation with a specific radiant density
From the above discussion, now we know about fundamental physics. And we know that, to do measurement in fundamental physics we use fundamental units. And any other units that we derive from them are called derived units. So, our correct answer is option A.

Note: We discussed units used in the SI system. Now, we should know more about the SI system. We should note that the International System of Units is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world. We should know about the derived units. In the SI system, these are formed by powers, products, or quotients of the base units and are potentially unlimited in number. Derived units are associated with derived quantities; for example, velocity is a quantity that is derived from the base quantities of time and length, and thus the SI derived unit is metre per second (symbol m/s).