Question

What are the features of standard unit

Answer 1

Answer:

• (i) It should be easily understandable.
• (ii) It should be changed with change in physical factors.
• (iii) It should not change with place or time.
• (iv) It should be easily duplicated.
• (v) It should be in accordance with the size of the quality to be measured.
• (vi) It should be properly defined

Explanation:

◉LET'S EXPLORE MORE

✯What is the SI Unit?

SI unit is an international system of measurements that are used universally in technical and scientific research to avoid the confusion with the units. Having a standard unit system is important because it helps the entire world to understand the measurements in one set of unit system.

✯SI Base Units

• These are the fundamental units and are considered as the building blocks of the system. All the other units are derived from the SI Base units. One of the examples is that the SI unit of mass is kilogram. This is often confused with grams.

✯SI Base Units List

There are 7 SI base units. The seven units along with their SI unit and symbol are given below:

• Unit of length, meter (m): Meter is the SI unit of length and is defined by taking the fixed value of the speed of light in vacuum. It is expressed as m.s-1.

• Unit of mass, kilogram (kg): Kilogram is the SI unit of mass and is defined by taking the fixed value of the Planck constant. It is expressed as kg.m2.s-1.

• Unit of time, second (s): Second is the SI unit of time and is defined by taking the fixed value of Cesium frequency. It is expressed as s1.

• Unit of electric current, ampere (A): Ampere is the SI unit of electric current and is defined by taking the fixed value of the elementary charge.

• Unit of thermodynamic temperature, Kelvin (K): Kelvin is the SI unit of thermodynamic temperature and is defined by taking the fixed value of Boltzmann constant k = 1.380649×10-23.

• Unit of the amount of substance, mole (mol): Mole is the SI unit of amount of substance and is defined by the fixed value of Avogadro constant NA. One mole contains 6.02214076×1023 elementary entities and is expressed as mol-1.

• Unit of luminous intensity, candela (cd): Candela is the SI unit of luminous intensity and is defined by the fixed value of the luminous efficacy.

✯SI Derived Units

The derived units are unlimited as they are formed by different operations on the base units. For derived units, the dimensions are expressed in terms of the dimensions of the base units. The derived units might also be expressed with the combination of base and derived units.

✯Advantages of Learning SI Units and CGS Units

• These units given in an interactive manner and is easily understandable to help the students learn better.

• The units and its explanation will help the students to get an in-depth idea about the respective topics.

• The units are given in points to helps students retain the concept for a longer period of time.