For a vibration magnetometer, the time period of bar magnet can be redcued by:

Options

A. Moving it towards south pole
B. Moving it towards north pole
C. Moving it towards equator
D. Anyone of them

Explanation

To solve the problem of how to reduce the time period of a bar magnet in a vibration magnetometer, we need to analyze the factors that influence the time period. The time period \( T \) of a bar magnet can be expressed using the formula:

\[ T = 2\pi \sqrt{\frac{I}{mB_H}} \]

Where:
- \( T \) is the time period,
- \( I \) is the moment of inertia of the bar magnet,
- \( m \) is the mass of the bar magnet,
- \( B_H \) is the horizontal component of the magnetic field.

### Step-by-Step Solution:

1. **Understand the Formula**:
The time period \( T \) is directly proportional to the square root of the moment of inertia \( I \) and inversely proportional to the horizontal component of the magnetic field \( B_H \).

2. **Identify the Factors**:
Since \( I \) (moment of inertia) and \( m \) (mass) are properties of the bar magnet and remain constant, the only way to reduce the time period \( T \) is to increase the horizontal component of the magnetic field \( B_H \).

3. **Analyze the Magnetic Field**:
The horizontal component of the Earth's magnetic field varies depending on the location. At the poles, the magnetic field is predominantly vertical, while at the equator, the horizontal component is maximized.

4. **Determine the Optimal Position**:
To increase \( B_H \), the bar magnet should be moved to a location where the horizontal component of the magnetic field is the strongest. This is at the equator, where the vertical component is minimal, and the horizontal component is maximal.

5. **Conclusion**:
Therefore, to reduce the time period of the bar magnet in a vibration magnetometer, the magnet should be moved to the equator.

### Final Answer:
The time period of a bar magnet in a vibration magnetometer can be reduced by moving it to the equator.

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