What type of cell is used in devices that require a photo conductive property?

The correct choice is the Cadmium sulfide (CdS) cell because it is specifically designed to exhibit photoconductive properties, meaning its electrical conductivity changes in response to light. CdS cells are commonly utilized in light-sensitive applications such as light meters, automatic lighting systems, and various electronic devices where light detection is essential.

The other types of cells listed serve different purposes. The lead-acid cell is primarily used for energy storage in batteries, particularly for vehicles. The NiCd cell, which is a nickel-cadmium rechargeable battery, is used in portable electronics and power tools, emphasizing energy discharge rather than light sensitivity. The silver oxide cell is often found in applications requiring stable voltage, such as in watches and hearing aids, and does not rely on a photoconductive response. Therefore, the CdS cell stands out for its unique ability to respond to changes in light conditions.