What type of conveyor relies solely on gravity for its operation?

The correct answer is gravity conveyor. A gravity conveyor is designed to move materials down a slope or on a level surface using the force of gravity. It typically consists of a series of rollers, wheels, or a flat surface that allows objects to slide along without the need for powered mechanisms. This type of conveyor is commonly used in warehouses and distribution centers, where items need to be transported from one area to another with minimal effort and cost.

In contrast, powered conveyors require a motor or some form of power source to operate. They utilize belts, chains, or other mechanisms to actively move materials. For instance, belt conveyors and chain conveyors both use power sources to transport products, which is not the case with a gravity conveyor.