Which one of the following is coated on the photographic plate?

Silver oxide
Silver Bromide
Silver chloride
Silver iodide

The correct answer is (c), silver chloride. Silver chloride is a light-sensitive compound that is used in photographic plates. When exposed to light, silver chloride breaks down into silver and chlorine gas. The silver is then deposited on the photographic plate, creating an image.

Silver oxide is not used in photographic plates because it is not light-sensitive. Silver bromide and silver iodide are also light-sensitive compounds, but they are not as sensitive to light as silver chloride. This means that they require more light to create an image, which can make them less practical for use in photographic plates.

In addition to being light-sensitive, silver chloride is also relatively inexpensive and easy to produce. This makes it a good choice for use in photographic plates.