What type of component is an MOV?

An MOV, or Metal Oxide Varistor, is classified as a varistor, which is a type of voltage-dependent resistor. Its primary function is to protect circuits by clamping voltage spikes and transients. When the voltage across the MOV exceeds a certain threshold, it changes its resistance significantly, becoming conductive and allowing excess current to bypass sensitive components. This helps to prevent damage from surges caused by electrical storms, switching operations, or other transient events.

While resistors, inductors, and capacitors are essential components in electronic circuits, they serve different functions; resistors limit current, inductors store energy in a magnetic field, and capacitors store energy in an electric field. The defining characteristic of a varistor, particularly an MOV, is its ability to respond to voltage levels, making it uniquely suited for surge protection in various applications, which is why it is the correct answer in this context.