Which of the following is a common application of ceramics in engineering?

Ceramics are widely used in engineering primarily due to their excellent insulating properties. Insulation refers to the ability of a material to resist the flow of electric current, which is crucial in various applications such as electrical components, high-voltage systems, and electronic devices. Ceramics can withstand high temperatures and have low thermal conductivity, making them ideal for use in insulators in electrical applications. Their chemical stability and resistance to thermal shock further enhance their performance in insulation roles.

In contrast, the other options do not align with the typical applications of ceramics. Electrical wiring is generally conducted through metals that excel in conductivity, while composite materials refer to combinations of different materials to achieve desired properties, which may not predominantly include ceramics. Liquid metals represent a completely different category of materials and are typically not associated with ceramics at all. Thus, insulation is indeed the most fitting application of ceramics in engineering contexts.