Question

A circular loop placed in a plane perpendicular to the plane of paper carries a current when the key in ON, [figure]. The current as seen from pionts A and B (in the plane of paper and on the axis of the coil) is anticlockwise and clockwise respectively. The magnetic field lines point from B to A. The N-pole of the resultant magnet is on the face close to:

A. (a) A
B. (b) B
C. (c) A if the current is small, and B if the current is large
D. (d) B if the current is small and A if the current is large

Answer 1

Correct Answer - A
Since the magnetic field lines point from B to A, it implies that they enter into B and emerge out of A. Clearly, the face close to A is the N-pole as field lines emerge out of north pole and enter into south pole.