True or False: Mutual capacitance is affected by the diameter of a conductor's insulating material.

Mutual capacitance refers to the capacity of two conductors to store charge relative to one another when they are coupled through their electric fields. The insulating material between these conductors plays a crucial role in defining the mutual capacitance as it influences the electric field and the dielectric constant of the materials involved. The diameter of a conductor's insulating material directly affects the capacitance because a larger diameter increases the surface area, which allows for greater interaction between the electric fields of the conductors. Additionally, a thicker insulating layer can reduce the electric field strength but also affect the capacitance due to the dielectric properties of the material.

Thus, understanding that mutual capacitance is indeed influenced by the diameter of the insulating material helps clarify why this statement is true. The properties of the insulating material, including its thickness and dielectric constant, combined with the conductor's dimensions, collectively determine the overall capacitance in the system.