Which of the following figures shows a correct representations of deviation and dispersion of light by a prism?

Options

A.
B.
C.
D.

Explanation

To determine which figure correctly represents the deviation and dispersion of light by a prism, we can analyze each option step by step.

### Step 1: Understanding Refraction and Dispersion
- **Refraction** occurs when light passes from one medium to another, causing it to change direction.
- **Dispersion** is the separation of light into its constituent colors (spectrum) when it passes through a prism.

### Step 2: Analyzing Each Option
1. **First Option**:
- The diagram shows refraction occurring at both surfaces of the prism.
- However, it incorrectly depicts dispersion occurring outside the prism, which is not accurate since dispersion occurs inside the prism.
- **Conclusion**: This option is incorrect.

2. **Second Option**:
- The ray of light is shown deviating, but there is no refraction depicted at the second surface of the prism.
- Since refraction is essential for deviation to occur, this representation is incomplete.
- **Conclusion**: This option is incorrect.

3. **Third Option**:
- This diagram correctly shows both refraction and dispersion occurring within the prism.
- The light is shown splitting into its constituent colors as it exits the prism.
- **Conclusion**: This option is correct.

4. **Fourth Option**:
- In this option, the red color is shown below and violet above. However, this is incorrect because violet light deviates more than red light due to its shorter wavelength.
- The correct order should show red at the top and violet at the bottom.
- **Conclusion**: This option is incorrect.

### Final Answer
- The **third option** is the only correct representation of deviation and dispersion of light by a prism.

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