How Does Ampere's Law Determine the Ranking of Loops by Enclosed Current?

[ZeroVersion]

Hellow every one I have small Q but I stuck on it

there is pic attachedhope to be interesting and clear to you

Homework Statement

rank the loops accoroding to the current enclosed greatest first

Homework Equations

we have three eqn's
B = u "node" I encِْْْْ
B = u"node" i / 2 pi r outside the wire
B = (u"node" i / 2 pi R² ) r inside the wire

The Attempt at a Solution

I knew the solotion but I do not know how did they get it

the soloution is d and c tie then b then a

 

[Doc Al]

Hint: Treat the current density as uniform across the wire.

 

[ZeroVersion]

thank you very much Doc al it is as what you mentioned related to the current density for c and d the current is the same whereas in b smaller and a is even smaller than b



Sometimes we think in very difficult method when we can solve it in easier way


Thank you again and regards​