To demagnetise a magnet using the heating method, which of the following is the coreect step?

Options

A. Heat the magnet to become red hot, and allow it to cool in the east-west direction.
B. Heat the magnet to become red hot, and allow it to cool in the north-south direction.
C. Heat the magnet in boiling water, and allow it to cool in the north-south direction.
D. Both (a) and (b).

Answer

To demagnetize a magnet using the heating method, follow these steps:

### Step-by-Step Solution:

1. **Heat the Magnet**: Start by heating the magnet until it becomes red hot. This is crucial because the heat disrupts the alignment of the magnetic domains within the magnet.

2. **Cool in the Correct Direction**: After the magnet has reached a red hot state, it is important to allow it to cool down in the East-West direction. This means positioning the magnet horizontally, with one end pointing East and the other pointing West.

3. **Understanding the Cooling Direction**: Cooling the magnet in the East-West direction is essential because if you cool it in the North-South direction, the magnet may realign itself back to its original magnetic state. By cooling it in the East-West direction, you can determine if the magnet has been successfully demagnetized.

4. **Check the Magnetization**: Once the magnet has cooled down, check its orientation. If it remains in the East-West position, it indicates that the magnet has been demagnetized. If it shifts back to the North-South position, then it has not been demagnetized.

### Conclusion:
The correct step to demagnetize a magnet using the heating method is to heat it until it becomes red hot and then allow it to cool in the East-West direction. Therefore, the correct answer is **Option 1**.

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