Question

Two loops carry equal currents I in the same direction. They are held in the positions shown in the figure and project above and below the plane of the paper. The point P lies exactly halfway between them on the line that joins their centers. The centers of the loops and the point P lie in the plane of the paper. Which one of the figures below shows the position of a compass needle if the compass were placed in the plane of the paper at P?

Answer 1

The direction of the magnetic field indicated can be remembered by the following rule:

"Curl the fingers of your right hand in the direction of the current around the loop - your thumb then indicates the direction of the magnetic field."

No using the above formula we see that the magnetic field is directed from left to the right through the loops i.s., parallel to the axis of the loops.so left hand side is magnetic south pole and righr hand side of the loops creates the magnetic north pole.Now if we place a compass niddle at position P obviously its direction of north pole is left hand side and that of south pole is right hand side.

So the right answer is option (d).