Correct Answer - Option 2 : Reproduction of light in motion picture
Photoelectric Cells:
The photoelectric cells work on the principle of the photoelectric effect
Photoelectric cells convert light energy into electrical energy.
Applications of photoelectric cells:
- Photoelectric cells are used in TV cameras for telecasting scenes.
- Reproduction of sound along with pictures in cinema.
- Used in counting devices.
- Used in burglar alarm and in fire alarm.
- Used to measure the temperature of stars.
- Used to switch on and off the street lighting system automatically.
- Used in photometry to compare the illuminating power of two sources.
- Used in industries to locate minor flows or holes in metallic sheets.
- Used as photoelectric sorters i.e. to sort out materials of different shades.
- Used to control chemical reactions etc.
