When the ray of light travles from an optically denser medium to optically rarer medium the maximum value of angle of refraction is

Options

A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. `90^(@)`

Answer

To solve the question regarding the maximum value of the angle of refraction when a ray of light travels from an optically denser medium to an optically rarer medium, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Refraction**:
- Refraction occurs when light travels from one medium to another, changing speed and direction. The two types of media mentioned are optically denser (higher refractive index) and optically rarer (lower refractive index).

2. **Identifying the Critical Angle**:
- When light travels from an optically denser medium to an optically rarer medium, there exists a specific angle called the critical angle (C). At this angle, the angle of refraction (R) is 90 degrees.

3. **Behavior of Light at the Critical Angle**:
- If the angle of incidence (I) is equal to the critical angle (C), the angle of refraction (R) will be 90 degrees. This means the light will travel along the boundary between the two media.

4. **Angles Greater than the Critical Angle**:
- If the angle of incidence (I) exceeds the critical angle (I > C), total internal reflection occurs, and no refraction happens. The light reflects back into the denser medium.

5. **Conclusion on Maximum Angle of Refraction**:
- Since the maximum angle of refraction occurs at the critical angle, and at this point, the angle of refraction is 90 degrees, we conclude that the maximum value of the angle of refraction when light travels from an optically denser medium to an optically rarer medium is 90 degrees.

### Final Answer:
The maximum value of the angle of refraction is **90 degrees**.

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