Description : Draw & describe construction of LDR
Last Answer : Description: 1. Photo resistors (or LDR) are manufactured from photo-conductive semiconductor materials such as cadmium sulphide (CdS), cadmium selenide (CdSe) and lead sulphide (PbS). 2 ... of photo resistors may be several mega ohms in total darkness and less than100Ω, when well illuminated.