Question

A magnetic compass needle is placed in the plane of paper near a point A. in which plane should a straight current carrying conductor be placed so that it passes through A and there is no change in the deflection of the compass? Under what condition is the deflection maximum and why?

Answer 1

the compass may be kept parallel to the point A to get no deflection
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the compass may be kept perpendicular to the point A to get the most deflection.

Answer 2

Explanation:

the compass is parralel to point A . so , there is no deflection .But when the compass is kept perpendicular to it shows the maximum deflection