State Board Commerce (XI-XII) - Test Papers
JEE MAIN & ADVANCE 11th PCM Chemistry – Structure of Atoms Demo Videos
Hello students we’re studying the chapter structure of atoms so in this model i will R continue what we were discussing there is the radial probability curves so already we discussed how to calculate the total probability right so for which we took a shell at distance R which is thickness dr and we can calculate the volume of it which is 4 PIRsquare into dr and probability of finding the electron in that small thickness dr it can be defined as DP which is side squared into DV whereas side square is the probability density function and which can be written as 4 pi r square side square into dr so the total probability we learned that I can integrate that from 0 to PDP and it comes to be r1 r2 size square 4pirsquare y a squared dr right so this is what we learned and hear that PR that’s what ever that has been defined in that integral part is what we called as the radial probability distribution function so therefore to calculate the total probability it is integral r1 to r2 PR into dr area where PR is the probability distribution function right this is what we learned earlier continuing this now we will try to draw the total probability versus the R so let’s see that first so if it all I draw the total probability vs. R here that p of R is the probability distribution function VS the R now at the nucleus r is equal to 0 so PR will be 0 so the graph will always start from the origin as R square increases side squared is actually decreasing so there are two functions one is the R squared part and the other one is the side squared part then what would happen the graph looks something like this for one its orbital what is this suggesting that initially size square is decreasing but the r-squared is increasing but as R is increasing size square is decreasing exponentially so initially it will increase because of the R squared and then it decreases because of the side squared so r square is contributing first in the first half of the graph and side square is contributing in the second half of the graph and eventually tends to become 0 now here you could see it is reaching a maximum value and maximum values what we call it as the radius of maximum probability and that is found to be 0.5- 9 Armstrong’s which is exactly the same work bored how calculate and let me a same it as a not now we know that according to bohr’s r is equal to 0.529 n square by z so if Z is constant for every value of n you should be getting a higher value of the radius right so which i can write it as a naught into n square by Z so from the graph it is everything that the probability of finding the electron said nucleus and infinite distance from the nucleus is always zero not let me draw a similar graph for two s so far two s if at all you see I have applauding probability distribution function versus R now this is the graph you will get now here what I would see is that we are getting a radial node here where the probability of finding an electron is 0 now this is the maximum distance are the peak where we have the highest probability and this distance amazingly matches to 4 a knot which is again suggesting from the bohr’s theory that radius will be a knot into n square so it is a second orbit so n square users 4 a knot so the radius of maximum probability of one s will always be less then 2 s so that is what we will get that means the electron into 2S is always found at the larger distance from the nucleus compared to the 1s of orbital know if I like keep drawing this for different orbital’s what do I get so total probability were probably this distribution curve vs r if it is 2s this is what we found and it has one radial Node with maximum radius of maximum probably at a distance similarly if I draw it for 2p i will get no nodes here this is how we will get with certain maximum distance similarly for 3p you will see it is quite similar to that of 2s similarly if at all I keep drawing it for again with the radial node here and if I draw for three D and then you would see this quite matching to that of 1s and 2p similarly if at all I draw it for 4 d you will see the graph varies quite similar to 2s and 3p with one radial node this gives us a pattern so here you would see there is one radial Node forming so this gives us a pattern that the total number of radial nodes will be equal to n minus L minus 1 so therefore to calculate the number of radial Nodes for any particular orbital . we can use this formula that is n minus L minus 1 so from there we can get what is the total number of radial nodes as we go for the next module we will see about the planar nodes or the angular nodes thank you
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
CLASS XI MH – PCMB Physics -Measurement Demo Videos
What are these quantities in physics called us weight you hear about it weight a person weight 20 kg length height a person’s height is 5.6 feet temperature it’s too cold the temperature today is 20 degrees Celsius it’s too hot the temperature is 45 degrees celsius temperature pressure the pressure inside a can is 20 kg per meter square basically pressure and time so what are these quantities or what so common in these quantities yes all these quantities are called as physical quantity weight height time length temperature pressure all these are called as physical quantity now what is a physical quantity how do you signify that they’re called a physical quantity how will come to know ahead in your topics when some physical quantity comes how to identify them that they are a physical quantity obviously you can see there’s a common thing in all these quantities which are written on the screen there’s a common thing that is these things can be measured yes can you measure the height of course yes can you measure the length of any kind of object yes can you measure the weight, weight of a body weight of a person yes can you measure time temperature pressure of obviously yes . anything which can measure is called as a physical quantity so basically let’s come to the definition of a physical quantity the first thing in your chapter a physical quantity is a quantity that can be measured is called as a physical quantity so any kind of a quantity which can be measured is called as a physical quantity examples you can go on length mass velocity temperature area volume density anything which comes to your mind which can be measured is called as a physical quantity let’s classify the physical quantity now the physical quantities are classified into two parts are two types the first kind of physical quantity is called as fundamental quantity and the second kind is called as derived quantity so fundamental quantity and derived quantity they are the classification for physical quantity or physical quantity is classified into fundamental quantity and derived Quantity let’s understand them one by one let’s understand first what is a fundamental quantity now if i consider fundamental quantity as the word suggests ok let’s read this definition of physical quantity which does not depend on any other physical quantity for its measurement is called as a fundamental physical quantity what does it mean it means it is that kind of a physical quantity which does not depend which does not you can say of correlate or you can say being produced by any other physical Quantity it’s a completely independent quantity so that’s why it’s called as a fundamental quantity now let’s understand by taking some examples obviously would be curious Ok. ok sir understood that the physical quantity which does not depend on any other physical quantity or which is completely independent is called as a fundamental physical quantity but give us some examples so here are some examples basically here’s the list of the enter fundamental quantities which we consider in this case fundamental quantities list we have got total seven ,seven fundamental quantities listed at below up in this case please understand them by heart them there are only seven fundamental quantities out of which we can derive some other but then independent quantities are only seven the first fundamental quantity is called as in this case length, length is the basic fundamental quantity whose SI units are taken as a meter and simple is taking the second fundamental quantity is mass SI units taken as in kilogram symbol kg the third fundamental quantity is time SI unit second symbol is a S understand this all these quantities which I’m listing our fundamental what do you mean by fundamental they do not depend on any other physical quantity for their existence or for their explanation if i consider mass if i consider time they do not depend on any other quantity like if i say the time is 2 hours then it does not depend on the length of a room it does not depend on the temperature of the country or you can see the space where you are standing time is time, time in this case is not dependent on any other physical quantity hence it’s called as a fundamental quantity let’s move on in the list the fourth fundamental quantities temperature SI units of temperature is Kelvin and symbol k. fifth quantity electric current yes electric current is a fundamental quantity it’s not a any other derived kind of a quantity ok so electric current SI units ampere represented as a symbol as A then luminous intensity its SI units are candela represented as cd in this case what does luminous intensity understand in this case what the explanation for That what does it mean will understand later first will just list down so luminous Intensity it’s SI units candela then there is a 7 thing amount of substance which is measured at SI units mole represented as a mol so there are seven fundamental qualities and these are the list of the seven fundamental quantities I just revise the seven fundamental quantities are length mass time temperature electric current luminous intensity and amount of substance here Now along with this there were two more extra supplementary quantities which derive later which would explain later they were not put in the list of the fundamental quantities but they were categorized in a different list called as a supplementary list or a supplementary quantity list and these two supplementary quantities are the first one is called as a plane angle SI units taken as radians and symbol taken as rad the second supplementary quantities solid angle represented as an SI unit steradion and symbol sr so it just remember there are seven fundamental quantities and there are two supplementary quantities
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
CLASS XI MH – PCMB Physics -Electromagnetic Wave Demo Videos
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.
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
CLASS XI MH – PCMB Maths -Complex Numbers Demo Videos
let’s take any natural number say 2 yes we can take two so can i right 2 as 2 + 0i so i can write natural number as a complex number let us take example of a whole number 0 0 , can be written as( zero + zero i) let us take example often integer say – 3, -3 can be written as (-3+0i) and if i take any real number any real number as in i can take any fraction or decimal value if i take 0.5, 0.5 can be written as 0.5 + 0i so what I want to conclude there is all these four values that is natural number whole number integers real numbers are nothing but complex numbers this is what the most important part of complex numbers is we have Z =a + ib there a is nothing but it is real part of z and it is denoted by RE of Z this part is very important from your entrance point of view they can ask you to find RE(Z)so what is RE(Z) nothing but a real part of Z and Ib is nothing but imaginary part of Z and it is denoted by Im (Z) now let us start some algebraic operations on complex numbers the first which we will be studying is addition of a complex numbers now consider the example you if Z1 & Z2 are two complex numbers ok Z1 has the value as a+ IB and Z2 has the value c +ID then that the edition will be given as that Z1 + Z2 is equal to a + C now that is I, I added the real part so i obtained it by adding the real part plus the imaginary parts will be added here this B plus D and I is common so you will gate I this is obtained by adding imaginary parts so the addition of the complex number turn out to be as( a + C + B + D)*. I now in the similar manner we will start with subtraction of a complex numbers same example let’s Z 1and Z2 be two complex numbers whose values are as follows then we will have Z1-Z2 as a – c that is we are subtracting the real part plus keep in mind about this positive sign the sign should not be – here it should Be plus the other term which we will obtain is b minus the other term will be D into I so this is obtained by subtracting the imaginary parts so keep in mind Z1- 82 is given by a – c plus B minus D into I.
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
CLASS XI MH – PCMB Maths-Circle Demo Videos
let us see if we can face some problems and if you can crack them immediately so are we ready with pen and paper ok let us go ahead. see the first question first question say is find the center and radius of each of the following Circles the first one is ready for us first is x square + y square equals 25 immediately everyone must have realized that this is type one, that is a standard Circle so if it is a standard circle we start off with comparison first has to be comparison, comparing the given equation with x square + y square equals a square what will get a square is equal to 25 perfect if a square is 25 I can say that means a will be 5. A, a was what right it was a radius so I got radius of the circle as five if the radius is 5 and if it is a standard circle I can immediately say the center of the circle is going to be( 0, 0) whereas the radius of the circle will be five is it very interesting and simple ok let us see the next one the next says is (X – 5 ) square +( y – 3) square equals 20 very nice everyone must have identified that this is that type two question if it is that type 2 again I’ll compare the equation given equation with our type 2 formula that is centered radius form so when I compared with center radius form on left hand side just observe there is (X – H )square if it is (X – H )square I can say H is five and we can say case three alright so H is 5 case three did you observe right hand side, right hand side gives r square is equal to 20 right so much will be R perfect R is going to be square root of 20 as simple as that so i can say a directly the center of this circle that is h , k is( five , three) where r is the radius of the circle is square root of 20 if i calculate a square root of 20 is nothing but 2 root 5 question 2 says find the equation of a circle with Center at origin and radius is 5 repeat find the equation of a circle with Center at origin center at origin center at the origin yes it is a type 1 type one problem as it is a standard circle if center-right origin we see it is a standard you remember that yes so if center of the circle is that origin and radius is a we have studied the equation is given by ( x square + y square) equals to a square very nice what is a there radius right I’ll be given radius ,yes radius is 4 so i can say here a value its 4 , so when i substitute a equation of the required circle will become x square + y square equals to a square that is 16.
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
CLASS XI MH – PCMB Chemistry -Nature of Chemmical Bond Demo Videos
To understand chemical bond let us consider two ions first one is a cation and cation is a positively charged ion and the second one is in anion and anions are negatively charged ions. now you must be thinking that what will happen between this cation and anion then between this cation and anion there will be some force of attraction is cations are positively charged and as anions and negatively charged this force of attraction is holding the two ions cations and anions together and to form something called as a compound then this force of attraction which holds the ions together to form a compound is called as a chemical bond let us consider two atoms atom one and atoms two ,even between this atom there will be some attraction called us force of attraction which is going to hold the Atom together in the molecule this force of attraction which holds the atom together in the molecule is called as a chemical bond so i can finally define chemical bond as the force of attraction which holds atoms or ions together in a molecule is called as the chemical bond.
Increase your scores by Studying with the BEST TEACHERS – Anytime and anywhere you want
