Question

At neutral points

• A. \( B>B_H \)
• B. \( B<B_H \)
• C. \( B = B_H \)
• D. \( B = 0 \)

Hint:

At neutral points, the magnetic fields of the magnet and the Earth are equal in magnitude but opposite in direction, resulting in no net magnetic field.

Answer 1

The Correct Option is C

Step 1: Understanding neutral points.
Neutral points are the locations where the magnetic field produced by the Earth (\( B_H \)) and the magnetic field produced by the magnet (\( B \)) cancel each other out. At these points, the net magnetic field is zero.
Step 2: Relationship between \( B \) and \( B_H \).
At neutral points, the magnetic field \( B \) created by the magnet is exactly equal to the horizontal component of the Earth's magnetic field \( B_H \). This results in the cancellation of the two fields.
Step 3: Elimination.
- (A) \( B>B_H \): Incorrect, the fields cancel out, so \( B \) cannot be greater.
- (B) \( B<B_H \): Incorrect, again the fields cancel out, so \( B \) cannot be less.
- (C) \( B = B_H \): Correct, at neutral points, the fields are equal and cancel each other.
- (D) \( B = 0 \): Incorrect, as the magnetic field is not zero at the neutral points.
Step 4: Conclusion.
Thus, at neutral points, \( B = B_H \).