(i) Strength of magnetic field decreases as the distance from conductor increases.

(ii) Strength of magnetic field increases with an increase in the magnitude of current flowing through the conductor.

Introduction

The strength of the magnetic field due to a current-carrying conductor depends on several factors. Understanding these factors is essential for comprehending the behavior of magnetic fields in various situations.

Factors affecting the strength of the magnetic field

There are four main factors that influence the strength of the magnetic field produced by a current-carrying conductor:

1. Current (I):
The magnitude of the electric current flowing through the conductor has a direct impact on the strength of the magnetic field. As the current increases, the magnetic field becomes stronger. This relationship is described by Ampere's Law, which states that the magnetic field is directly proportional to the current.

2. Distance from the conductor (r):
The distance from the current-carrying conductor also affects the strength of the magnetic field. The field strength decreases as the distance from the conductor increases. This relationship follows the inverse-square law, meaning that the field strength decreases with the square of the distance.

3. Number of turns (N):
If the conductor is in the form of a coil or solenoid with multiple turns, the strength of the magnetic field increases with the number of turns. This occurs because each turn contributes to the overall magnetic field, resulting in a stronger field.

4. Permeability of the medium (μ):
The permeability of the medium surrounding the conductor also influences the strength of the magnetic field. The permeability determines how easily the magnetic field lines pass through the medium. In a vacuum or air, the permeability is denoted as μ₀ and has a constant value. However, in other materials, such as iron or steel, the permeability can be significantly higher than μ₀. The higher the permeability, the stronger the magnetic field produced by the current-carrying conductor.

Conclusion

The strength of the magnetic field due to a current-carrying conductor depends on the current, distance from the conductor, number of turns, and the permeability of the medium. Understanding these factors is crucial for analyzing and predicting the behavior of magnetic fields in various scenarios.