When can we use Ampere's Law to find Magnetic Field?

In this video, I go over the different cases where we can use Ampere's Law to find the magnetic field - in particular, when we have an infinite wire, cylinder, and sheet. I discuss *why* this is, and in general what needs to be true to solve for the magnetic field using Ampere's Law. I also go over cases where we cannot use ampere's law, in addition to how to use superposition to solve more complex problems.

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This is part of my series on introductory electromagnetism, where we explore one of the fundamental forces of nature - how your phone charges and communicates with the rest of the world, why you should be afraid of the sun, and the fundamentals of electric and magnetic forces and fields, voltages,

[RandomBoy_o]

Good evening sir very nice video, sir I had one doubt : I think the curl form of amperes law is still valid. Even though we cannot take B out from its stokes theorem form (integral B.dl). But I didn't find the use of symmetry in the proof of amperes law in Griffiths electrodynamics
Since I am a student (new to this formalism)whenever possible kindly let me know where did we use symmetry in the proof.
Also if we consider a circular loop around a finite wire magnetic field is constant(in magnitude)along the entire length of the loop at a particular position of loop. Which yeilds the same ans as that of an infinite wire.
What did you exactly mean by saying that magnetic field can not be take. Outside the integral.
For a fixed position of loop it can be taken out.