Photographic films or plates have …… as an essential ingredient.

Options

A. Silver Oxide
B. Silver Bromide
C. Silver Thiosulphate
D. Silver Nitrate

Answer

To solve the question regarding the essential ingredient in photographic films or plates, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Composition of Photographic Films**:
Photographic films or plates consist of a base material (like glass or celluloid) that is coated with a light-sensitive emulsion.

**Hint**: Remember that photographic films need to react to light to capture images.

2. **Identify the Light-Sensitive Compounds**:
The emulsion typically contains silver halides, which are compounds of silver and halogens. The most common silver halides used in photography are silver bromide (AgBr), silver chloride (AgCl), and silver iodide (AgI).

**Hint**: Think about which silver compounds are known for their sensitivity to light.

3. **Evaluate the Given Options**:
The options provided are:
- Silver oxide (Ag2O)
- Silver bromide (AgBr)
- Silver thiosulphate (Ag2S2O3)
- Silver nitrate (AgNO3)

Among these, we need to determine which one is primarily used in photographic films.

**Hint**: Recall that silver bromide is specifically known for its use in photographic processes.

4. **Select the Correct Answer**:
Silver bromide (AgBr) is the essential ingredient in photographic films due to its high sensitivity to light, which allows it to capture images effectively.

**Hint**: Focus on the properties of the compounds and their applications in photography.

### Final Answer:
Photographic films or plates have **silver bromide (AgBr)** as an essential ingredient.