Question

The neutral point in a magnetic field is a point at which
A.)The resultant magnetic intensity is zero
B.)Earth’s field is zero
C.)The magnetic field is zero
D.)The magnetism is more

Answer 1

Hint: In a region where there are two magnetic fields, the points where the direction of one field is equal in magnitude and opposite in direction to the other magnetic field, the resultant magnetic field becomes zero.

Detailed step by step solution:
A bar magnet produces a magnetic field around it. The magnetic lines of force look like this.

Outside the magnet, the lines start from the north pole and end at the south pole of the magnet while inside the magnet, they start at the south pole and end at the north pole.

Even if this magnet is kept in isolation from other magnetic fields, there is a magnetic field of earth always around it. The points horizontal where the horizontal component of earth’s magnetic field has equal magnitude and opposite direction to the field of the bar magnet, the two fields cancel each other and resultant magnetic field intensity at those particular points is zero. These points are called neutral points. Neutral points can be observed between any two fields interacting with each other and not just the magnetic field of earth.

When the poles of the bar magnet are aligned with the poles of earth’s magnetic field then we observe two neutral points on either side of the magnet. When a magnetic compass is placed at the neutral points, it comes to rest in any random direction.

From this discussion, we can say that the correct answer to the question is option A.

Note: To obtain the neutral points on either side of the magnet, the alignment of the magnet in earth’s magnetic field is done in such a way that magnet’s north points to earth’s magnetic south and the magnet is parallel to the magnetic meridian of earth.