The magnetic moment of a bar magnet of length 20cm is `3.6 xx 10^(-6)A-m^(2)`. The magnetic length is 90% of its geometric length. Then find the pole strength of the magnet.

Explanation

To find the pole strength of the magnet, we can use the relationship between the magnetic moment (M), pole strength (m), and magnetic length (l_m):

1. **Identify the given values:**
- Magnetic moment, \( M = 3.6 \times 10^{-6} \, \text{A-m}^2 \)
- Geometric length, \( L = 20 \, \text{cm} = 20 \times 10^{-2} \, \text{m} = 0.20 \, \text{m} \)
- Magnetic length, \( l_m = 90\% \) of geometric length.

2. **Calculate the magnetic length:**
...