A bar magnet is kept in the earth's magnetic field with its north pole pointing earth's north. The distance between the null point is 20 cm. If earth's horizontal magnetic field is ` 4 xx 10^(-5)T`, then find the magnetic moment of the magnet.

Explanation

To solve the problem, we need to find the magnetic moment of the bar magnet when it is placed in the Earth's magnetic field.

### Given:
- Distance between the null points (d) = 20 cm = 0.2 m
- Earth's horizontal magnetic field (B) = \(4 \times 10^{-5}\) T

### Step-by-Step Solution:

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