Which of the following factors does NOT determine the strength of a magnetic field in a coil?

The strength of a magnetic field in a coil is influenced by several factors, and understanding these can help clarify the relationships involved. The material used in the core of the coil plays a significant role because different materials have varying permeability, which affects how easily the magnetic field lines can pass through them. An increase in the number of turns in the coil amplifies the magnetic field, as each turn contributes to the overall field strength. Additionally, the amount of current flowing through the coil directly influences the magnetic field, with higher currents producing stronger fields.

Distance from the coil does not determine the strength of the magnetic field generated within the coil itself; rather, it affects the intensity of the magnetic field experienced at a certain point away from the coil. As one moves away from the coil, the magnetic field strength diminishes, but this attenuation is not a factor that influences the field strength generated by the coil's properties and configuration at its source.