the last post i posted was wrong due to my superb english on net n my failure to reply due to my xams
so now
whenever we calculate magnetic field due to a solenoid or a wire from amperes law or the same by gaus law for different objects we use the fact abt symmetry fine. but suppose say i am a scientis and hv invented a solenoid so that time we cant calculate magnetic field at the centre of the solenoid by ampers law as we dont know the symmetry . so we hv to use the conventional laws of coulumbs/biot savart law........
so my question is that amperes law/gauss law is valid only in theory buks for practical situtations we hv to resort to other lwas and then calculate whether it is a spherical /cylindrical symmetry n then when can use ampers law isnt it
-
UP 0 DOWN 0 0 4
4 Answers
49varun bhai try to be clear in asking ur questions!!!
like u can use hindi if u have problem wid english ... mai to wahi karta hoon if u look at some of my posts!
But i think he is trying to say that:
While measuring a field inside a solenoid, what we try to do is make the field OUTSIDE the solenoid 0 and so consider INFINITE LENGTH!
Similarly in case of trying to measure field due to a conducting wire, we NEGLECT fringing effect or in that sense consider the wire to be infinitely long!!
But in actual practice, those things are NOT possible in real life...so i think basically he is trying to say that Ampere's circuital law or Gauss law...which are used to measure the respective fields...are they of any use in real life? Or are they useful only in solving those HYPOTHETICAL cases?
I AM NOT WRONG...RGHT?? WASN'T THAT THE INTENDED QUESTION??
1yeah subhomay actually my englishs gud only in writing so yeh what i am truing to say is that guass law and amperes law r valid only in special cases like that of a magneitc field due to an infinte wire we know thers a cylindircal symmetry thats y can use amperes law
so actuallly we know the answer that is there cylindrical symmetry thats y we solve it means we know the answer n we r just using some another method to back check the anwer (something we do in maths or phyiscs putting the answer n working backwards) isnt it ...... it can be used only for back checking. n nothing else...
49the actual application of gauss law or circuital law is not to find out the field instead they can be directly used to find the no. o flux lines or amount of current knowledge through the area covered by a loop with the help of a pre-knowledge of the field associated...
these laws can be used to find out the field in case the mathematics involved is simpler than the other laws that give the fields...else it is just meaningless for physicists to solve them by the long mathematical processes involved by gauss law...
gauss law becomes easy to work with once we start taking symmetric bodies..coz then we can take the field component out of integration as it becomes constant!!!
so the working becomes feasible!!!!!
AFTER ALL GAUSS LAW IS NOTHING BUT A NOBEL PRIZE WINNING EQUATION WHICH IS AS OBVIOUS AS 1+1=2!!!!