Answer to Question #63012 in Differential Equations for hamid

Question

The general solution of
d2B/dr2+dB/rdr-B/a^2 =0
is B=C Io(r a) +D Ko(r/a)
In our particular case the solution is Ko.
How we get
B= (h/2 phi a^2) Ko(r/a)
Where h= magnetic flux= Integral B d2r. Phi=3.14. And a=(m/meu. n e^2) 1/2