A short bar magnet has a magnetic moment of 10 `Am^(2)`.If its length is 10 cm,then the pole strength of the dipole is

Options

A. (a)200 A m
B. (b)100 A m
C. (c)300 A m
D. (d)50 A m

Answer

To find the pole strength of a short bar magnet given its magnetic moment and length, we can use the formula for the magnetic moment (M) of a magnetic dipole:

\[ M = P \times L \]

Where:
- \( M \) is the magnetic moment,
- \( P \) is the pole strength,
- \( L \) is the length of the magnet.

### Step-by-Step Solution:

1. **Identify the given values:**
- Magnetic moment \( M = 10 \, \text{Am}^2 \)
- Length of the magnet \( L = 10 \, \text{cm} = 10 \times 10^{-2} \, \text{m} = 0.1 \, \text{m} \)

2. **Rearrange the formula to solve for pole strength \( P \):**
\[ P = \frac{M}{L} \]

3. **Substitute the known values into the formula:**
\[ P = \frac{10 \, \text{Am}^2}{0.1 \, \text{m}} \]

4. **Calculate the pole strength:**
\[ P = \frac{10}{0.1} = 100 \, \text{A} \]

5. **Conclusion:**
The pole strength of the dipole is \( 100 \, \text{A} \).

### Final Answer:
The pole strength of the dipole is \( 100 \, \text{A} \).

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