Question

A horizontal circular loop carries a current that looks clockwise when viewed from above. It is placed by an equivalent magnetic dipole consisting of a south pole $S$ and a north pole $N$.

• A. The line $SN$ should be along a diameter of the loop.
• B. The line $SN$ should be perpendicular to the plane of the loop.
• C. The south pole should be below the loop.
• D. The north pole should be below the loop.

Answer 1

Answer: (B), (D)

The line $SN$ should be perpendicular to the plane of the loop.
The north pole should be below the loop.

Since a current carrying circular loop behaves as a magnetic dipole whose magnetic moment's direction is perpendicular to the plane of the circular loop.
therefore, when this dipole is replaced by equivalent bar magnet then the line joining NS will be perpendicular to the plane of the loop
Now the direction of current flowing through the loop is clockwise when viewed from the top.
Therefore, magnetic field at the center of the loop is inwards therefore, South pole of the magnet should be above the plane and North pole of the magnet should be below the plane.