You are by far the top 2 best science lecturers i have come across on the internet or in real life. You must have been one of the top students in India. All your lectures and explainations are extremely clear. For a medical doctor wanting to study engineering and QM, this is great
Total no of allowed state of energy value En ,by allowed state we means that the state may be occupied or not..But it is permitted , NOW ( in 32.02) it is written as N (the density of occupied state). Should not be it D because D is density of allowed space?
+rouadkjq Remember here he is doing the calculation in 'n space'. As we know 'n' can only take integer values i.e 1,2,3.. etc. So the volume of a single state in this space can be calculated based on the smallest integer value that is allowed. Which is 1 in all the three dimension. 1*1*1= 1.
because when you draw the sphere in cartesian coordinates, 1/8th of the sphere comes under the +x, +y and +z directions. since the density of states is a positive value, we multiply by 1/8
k=n (pie)/a since k can have only positive value implies n will have positive value only. why would k will have positive value? 1) k=-{2mE}/(h cut)^2 ...since for 1D potential well E is -ve (E
As the electron forms standing wave,both the positive and negative direction of propagation vector k is taken care by using single n values. And hence there is no need to take negative n values.
Wonderfully clear and concise! One of the best lecturers I have ever seen!
You are by far the top 2 best science lecturers i have come across on the internet or in real life. You must have been one of the top students in India. All your lectures and explainations are extremely clear. For a medical doctor wanting to study engineering and QM, this is great
Who is the other one?
what can I say other than BEST TEACHER.... you are fantastic and inspiring
Thanks for your valuable lectures. You are simply the best teacher ...... of course your students are really lucky.
what to say other than that your lectures are "THE BEST".
lucky are your students........
Undoubtedly the best lecture I have seen!!
Great teaching by a great teacher...🙏
Thanks so much for these materials. They have been really helpful sir.
thanx so much for this!
Very helpful..!!
thank you!
He is my God!
Total no of allowed state of energy value En ,by allowed state we means that the state may be occupied or not..But it is permitted , NOW ( in 32.02) it is written as N (the density of occupied state). Should not be it D because D is density of allowed space?
Yeah we can replace N with D but the meaning doesn't change. You can check at 46:29 the prof mentions it..!!
Wonderfull ! but i didn't know why the volume of a single state is 1 .
+rouadkjq Remember here he is doing the calculation in 'n space'. As we know 'n' can only take integer values i.e 1,2,3.. etc. So the volume of a single state in this space can be calculated based on the smallest integer value that is allowed. Which is 1 in all the three dimension. 1*1*1= 1.
+Naveen Shetty ok, but then It would be: Volume= (1/8) (4/3) pi() 1^3... no? Can you please explain a bit more?
Sir actually if you divide the quadrant into three axes it will be 4
So we need to multiple with 1/4.
@@rackshnadevie2871 no no. There are 8 octant in 3d.
In 2d only there are 4 quadrant
@@cheemsismyfrd tq sir!
Why multiplying it by 1/8
I can't understand
Please explain it bit more sir.
because when you draw the sphere in cartesian coordinates, 1/8th of the sphere comes under the +x, +y and +z directions. since the density of states is a positive value, we multiply by 1/8
@@rishkaravishankar5713 thank you got it
why divided by 1/8
because only possible value of "n" is positive and leads to 1st octant of sphere only.
@@alokkumar3703 Thank you.
Why we need to only positive values of nx ,ny,nz
k=n (pie)/a
since k can have only positive value
implies n will have positive value only.
why would k will have positive value?
1) k=-{2mE}/(h cut)^2 ...since for 1D potential well E is -ve (E
As the electron forms standing wave,both the positive and negative direction of propagation vector k is taken care by using single n values. And hence there is no need to take negative n values.
hi