Introduction:
A north pole of strength pie A m is moved around a circle of radius 10 cm, which lies around a long straight conductor carrying a current of 10A. In this scenario, we need to determine the work done.

Understanding the Scenario:
To understand the work done, we need to consider the interaction between the north pole and the current-carrying conductor. When a magnetic field interacts with a current-carrying conductor, a force is exerted on the conductor. This force is given by the formula:

F = BIL

Where:
- F is the force exerted on the conductor
- B is the magnetic field strength
- I is the current flowing through the conductor
- L is the length of the conductor

Calculating the Magnetic Field Strength:
In this case, the magnetic field strength can be calculated using Ampere's Law, which states that the magnetic field around a long straight conductor is directly proportional to the current and inversely proportional to the distance from the conductor. The formula is given by:

B = (μ₀ * I) / (2πr)

Where:
- B is the magnetic field strength
- μ₀ is the permeability of free space (4π * 10⁻⁷ T m/A)
- I is the current flowing through the conductor
- r is the distance from the conductor

Substituting the values into the formula, we can calculate the magnetic field strength:

B = (4π * 10⁻⁷ T m/A * 10A) / (2π * 0.1m)
B = 2 * 10⁻⁶ T

Calculating the Force:
Using the formula F = BIL, we can calculate the force exerted on the conductor. The length of the conductor is not mentioned in the given scenario, so we cannot determine the exact force. However, we can conclude that a force is acting on the conductor.

Calculating the Work Done:
The work done can be calculated using the formula:

Work = Force * Distance

In this case, the north pole is moved around a circle of radius 10 cm, which is equivalent to a distance of 0.1 m. Since the force is acting perpendicular to the direction of motion, the work done is given by:

Work = F * d * cos(90°)
Work = F * d * 0
Work = 0

Conclusion:
In this scenario, the work done is zero. This is because the force acting on the conductor is always perpendicular to the direction of motion. Therefore, no work is done in moving the north pole around the circle.