What are common types of electrical insulators used in overhead power lines?

The correct answer is rooted in the specific functions and designs of the components used to support and insulate overhead power lines. Pin insulators, suspension insulators, and strain insulators are all key types tailored for high-voltage applications.

Pin insulators are typically used in smaller-scale overhead systems, where they attach directly to poles. They function to isolate the conductor from the pole and can support the weight and tension of the line.

Suspension insulators are designed to hold conductors in a vertical arrangement and are often used in applications where longer spans between poles are required. These insulators help to accommodate thermal expansion and other physical stresses on the line.

Strain insulators are essential in areas where significant mechanical stress occurs, such as at the ends of long cable runs or at tension points. They can handle the pulling forces of the lines created by wind or load.

The other options listed include types of insulators that are either not commonly associated with overhead power lines or are specific to different applications. For example, pole insulators and shoe insulators do not represent the primary insulators used in standard overhead configurations, while substation and transformer insulators pertain to specific components within a power system rather than the overhead lines themselves.