What term describes devices that are solid and have no moving parts?

The term that accurately describes devices that are solid and have no moving parts is "solid-state devices." These devices operate based on the electronic properties of solid materials, typically semiconductors, and they are commonly used in various applications, such as transistors, diodes, and integrated circuits. The absence of moving parts is significant because it often results in greater reliability, lower power consumption, and less susceptibility to mechanical failure compared to other types of devices.

In contrast, fluid devices rely on the movement of fluids to operate, while mechanical devices generally involve moving parts to function. Energized devices could imply devices that require a source of power to operate, which does not specifically address the solid-state nature of the devices in question. Thus, "solid-state devices" stands out as the most accurate descriptor for devices that are inherently solid and motionless.