I've just been introduced to Ampere's circuital Law to calculate magnetic field. I saw in a derivation for the magnetic field inside hollow straight current carrying conductor that the integral of B.dl was zero because no current was passing through the surface of the loop. This was used to imply B=0.
However, it is mentioned ∫B.dl=0 does not mean B=0 at every point on the loop. I'm confused since ∫dl (length of loop) cannot be zero therefore B has to be zero. Where am I wrong?
The Attempt at a Solution
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