How Many Fundamental Units are There

Introduction

We get the count of the Fundamental Units as seven only. Basically, be it biology or physics or whatever subject it is, the term “unit” is common. In physics or mathematics, we come across numerous physical quantities which we require to measure. As such, measuring some volume or weight is very common in our daily life also. Isn’t it? Suppose by adding some units of measurement (like a milligram, rupees, etc.) with any number, we can enhance its meaning. The phrases 7080 kg of milk chocolate or 7080 dollars definitely imply some physical quantity. This concept of the Fundamental Unit may not be new to us. Here we will take a deeper look into it.

What is a Fundamental Unit?

Whenever we find some physical quantity that is fundamentally unique and cannot be derived from any other physical quantity, we call it a fundamental quantity.

It follows that we, definitely, need some units for its measurement. Here comes the definition of the Fundamental Unit.

The unit that is used to measure any fundamental quantity and from which other units can be derived is known as the Fundamental Unit.

What are The Fundamental Quantities?

There is a universal acceptance of some systems for measuring all physical quantities. Such well-defined systems are the International System of Units (SI) system, the MKS(Meter Kilogram Second) system, the foot-pound-second (fps) System, etc.

According to the SI system, the following are the fundamental quantities.

• Mass

• Length

• Time

• Amount of substance

• Thermodynamic temperature

• Electric current

• Luminous intensity

The Types of The Fundamental Units

As it goes without saying that each fundamental quantity has its unit, which we say the Fundamental Unit

Abiding by the SI system, the following are the fundamental units.

• The kilogram is the fundamental unit of Mass.

• The meter is the fundamental unit of Length.

• Second is the fundamental unit of Time.

• Mole is the fundamental unit of the Amount of substance.

• Kelvin is the fundamental unit of Thermodynamic temperature.

• Ampere is the fundamental unit of Electric current.

• Candela is the fundamental unit of Luminous intensity.

The Different Uses of The Fundamental Units

The fundamental units find their application in many ways, some of which are as follows.

• The units of the derived quantities can be derived from the fundamental units.

• The fundamental units help in naming the systems of measurement where the MKS system, the CGS system, etc.

• All the physical quantities, be they the fundamental ones or the derived ones, can be expressed in dimensional form based on these fundamental units.

Conclusion

• The MKS system is formed from the first letters of metre, kilogram and second; which are the fundamental units of length, mass and time respectively.

• The CGS system is the abbreviation where the letter “c” stands for centimetre, the letter “g” stands for the gram and the letter “s” stands for a second.

Here, we can easily identify that centimetre, gram and second are the fundamental units of length, mass and time respectively.

• The FPS system is obtained from the starting letters of the foot, pound and second; which are the fundamental units of length, mass and time respectively.

• There are two supplementary units defined in addition to the seven fundamental units. The supplementary units of the SI system are radian and steradian.

• Radian is the fundamental unit of measurement of any plane angle.

• Steradian is the fundamental unit of measurement of any solid angle.