the way professor uses (r) to denote vectors is the main cause of this confusion, try replacing (a) with (r) then integrate D.ds for top and bottom surface. Also, Z = h/2 for top surface.
Formula of divergence for cylinderical co ordinates is 1/r(d(rf)/dr)+ 1/rdf/dphi(phi direction) + df/dz in first term multiply r with function and than partial differentiate
@@akhilsm6840 it is according to the cylindrical coordinate system . a is distance from origin in horizontal plane and z is distance from origin to the point in vertical plane .
@@sakshamsahdev3468 hi can you please explain how does integration od D.ds come to 3πa^2h it should be 4 πa^2h by adding all components of top curved and bottom. Please clarify this. Thanks.
@@sarvjitpatil19 ya watch my comment in which I have written that instead of ((h)) ther will be ((h/2))... And then calculate it will come 3piasqaredh rather than 4...
the way professor uses (r) to denote vectors is the main cause of this confusion, try replacing (a) with (r) then integrate D.ds for top and bottom surface. Also, Z = h/2 for top surface.
21:19 sir it is 4πa2h na not 3πa2h
Formula of divergence for cylinderical co ordinates is
1/r(d(rf)/dr)+ 1/rdf/dphi(phi direction) + df/dz
in first term multiply r with function and than partial differentiate
sir in top and bottom flux calculations at 20:55 instead of (( h)) there will ((h/2)).
Since cylinder is from -h/2 to h/2 not from -h to h
Sir is considered the height of cylinder is h
agreee
well "half a loaf is better than nothing" thanks sir for helping …………...
Could u pls tell me how vector d became ar + zz
@@akhilsm6840 it is according to the cylindrical coordinate system . a is distance from origin in horizontal plane and z is distance from origin to the point in vertical plane .
at 26:58 why did you say that we cannot apply gauss's law here.. Please state the reasons Sir...
Del.d =3 by direct aplication of the formula for the given d and del for cylindrical surface
i think it must be 4piAsquareH,and then he compared it using gauss divergence theorum,and ended up with del.D=4 and dv=piAsquareH
sir is correct … he told divergence = limit of flux per unit volume
apply this formula you will get your (three) …..
think first and then comment …….
@@sakshamsahdev3468 hi can you please explain how does integration od D.ds come to 3πa^2h it should be 4 πa^2h by adding all components of top curved and bottom. Please clarify this. Thanks.
@@sarvjitpatil19 ya watch my comment in which I have written that instead of ((h)) ther will be ((h/2))... And then calculate it will come 3piasqaredh rather than 4...
@@sakshamsahdev3468 i tried but 2 of 2π and 1/2 of h gets cancelled and it comes a^2hπ for top as well as bottom and adding these we get
4 a^2hπ.
how del.D is 3 at 23:00......
Kuch jagah yeh direct values likhty hai...phly complictd krty fr chod dety...not well taught
well this time sir is correct because he told that divergence of D is limit of flux per unit volume ………
think yourself ………..
del.D = 3 kaise hua 23:00 mein????
divergence in cylindrical co-ordinate.. del ka formula hai udhar se hi aya