A magnetic compass needle is placed in the plane of paper near point A as shown in Figure 13.6. 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?
Explanation:-
By using right-hand thumb rule, we can find out the direction of magnetic field due to a current-carrying wire. These field lines form a circle in a plane perpendicular to the wire.
- In the given case; If we keep the wire in the plane of paper, it will cause magnetic field perpendicular to the plane. The field will be parallel to the vertical axis of a compass needle. As a result, there will be no change in the deflection of compass needle.
- The deflection is maximum when the wire through point A is perpendicular to the plane of paper. In that case, the field due to is parallel to the plane of the paper