What is the work done in taking a north pole of strength m around a long and straight conductor in a circular path at a perpendicular distance of r from the straight conductor?

Explanation

To solve the problem of calculating the work done in taking a north pole of strength \( m \) around a long and straight conductor in a circular path at a perpendicular distance \( r \) from the conductor, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Work Done**:
Work done \( W \) is defined as the product of the force \( F \) acting on an object and the displacement \( d \) of that object in the direction of the force. Mathematically, it can be expressed as:
\[
W = F \cdot d = F \cdot d \cdot \cos(\theta)
...