After 130 years, Definition of Kilogram is decided to change and update by India and it was approved on 20/May/2019.
Last year, During 26th meet of General Conference on Weights and Measures, it was decided to update previous definition of kilogram
In this meet there is also decided to update other definitions of some other physical quantities like Ampere, Kelvin and mole.
What was you study- The old definition;
As former definition is based on physical object that is the cylinder which made up of platinum-iridium.
This cylinder is affected by atmospheric contaminants as fine dust particles and other atmospheric factors as temperature and humidity which shows imbalances in weight of this cylinder.
So, It is decided to change the definition of kilogram.
New Definition
New definition of kilogram is now not dependent on any physical object (Platinum- iridium cylinder).
Updated definition of kilogram is based on one of the concept of physics that is planck's constant.
As, Planck's constant (h) is very small number therefore to measure this, the research scientist Dr Bryan Kibble decided to built a super-accurate set of scales which will introduce by the name of Kibble balance. It has an electromagnet which pulls down on one side of the scales and a weight - say, a kilogram - on the other.
Indian scientific committee decided to change these definitions of physical quantities and for this CSIR's (Council of Scientific & Industrial Research), National physical laboratory requested to Educational Organisations to update text books in schools, colleges, engineering and other courses.
Write on comment to know more about kibble balance.
very nice