Students welcome all for a geography lessons which is embedded in your physics chapter of electromagnetic waves before starting with the geography first question why are we starting this so-called structure of atmosphere last time we completed the idea of something called electromagnetic waves which are wireless, wireless means no wives in but obvious they travel through the air what is air? atmosphere but obvious you have to study the idea of entire layers of atmosphere is so simple the very first learn the yellow is troposphere about that that is the mesosphere followed by the thermo sphere then you have exosphere and all white color patch that blue part is your ozone layer why do we have but what are you expected in your examinations is the following table different layer of atmosphere let’s start naming them first layer is your TROPO,STRATO, MESO , IONO ,THERMO. let me tell you one thing THERMO is a baby of ionosphere but obvious these are the layers and the first thing which will be studying is the height but more of what about the height. let me ask you one thing is a height in centimeters no meter oh no then it’s kilometers that’s it 0- 12 kilometers but one kilometer is too big it’s beyond imagination you do want to prove ok . which is the tallest tower in the entire world. bhurj Khalifa what’s the approximate height 800 meters in 800 meters not even one kilometer not even one so now imagine to 12 kilometer about khalifa you to place to 12 more khalifas us till then you will get the idea of troposphere for you welcome to the structure of atmosphere then we have your stratosphere which goes from well 12-50 kilometers MESO 80,IONO 400 and THERMO being a baby of IONO Oh goes up to 110 .so you can remember the upper values so once again. TROPO 12, STRATO 50, MESO 80 ,IONO 400 ,THERMO 110 what is the density of air taken as one as you go up density goes on decreasing the reason is less number of molecules less number of molecules less dense so the idea here is one is the density one means what means 10 raise to 0 and look look at the values we get the values Look, look, look, quite difficult how many values have to remember no no you remember the values you remember the technique to remember the values how exactly it would be simple if you look at one it’s 10 raise to 0 at kilogram per meter cube is just a unit so it’s like as i go up of course in the atmosphere so it will be like 0 to- 1,-1 to- 3, -3 t0 -5, -5 to -10, 0 to- 1, -1 to- 3, -3 t0 -5, -5 to -10 Oh simple and easy.