The iron core carries two windings (picture). One winding, of a large number n of turns, is connected to a source of sinusoidal emf E. The other winding consists of one homogeneous ring, the resistance of which is R. Points A, B, C of this ring are spaced from each other at equal distances. If an AC ammeter with resistance r is connected to two of these points, what will it show? Consider two connection options indicated in the figure.

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