Applications of photoelectric cells are as follows:
(i) Photoelectric cells are used for reproducing sound in cinematography.
(ii) They are used for controlling the temperature of furnaces.
(iii) Photoelectric cells are used for automatic switching on and off the street lights.
(iv) Photoelectric cells are used in the study of temperature and spectra of stars.
(v) Photoelectric cells are also used in obtaining electrical energy from sunlight during space travel.