Which of the following statement is `//` are correct about the refraction of light from a plane surface when light rays is incident in denser medium. `[` C is critical angle `]`

Options

A. The maximum angle of deviation during refraction is `(pi//2)-C`, it will be at angle of incidence C
B. The maximum angle of deviation for all angles of incidence is `pi-2C`, when angle of incidence is slightly greater than C
C. If angle of incidence is less than C, then deviation increases if angle of incidence ia also inicreased
D. If angle of incidence is greater than C, then angle of deviation decreases if angle of incidence is increased

Explanation

To solve the question regarding the refraction of light from a plane surface when light rays are incident in a denser medium, we need to analyze the statements provided and determine their correctness based on the principles of optics.

### Step-by-Step Solution:

1. **Understanding Refraction**:
- Refraction occurs when light passes from one medium to another, causing a change in its speed and direction. When light travels from a denser medium to a rarer medium, it bends away from the normal.

2. **Critical Angle (C)**:
- The critical angle (C) is defined as the angle of incidence above which total internal reflection occurs. It can be calculated using Snell's Law:
\[ n_1 \sin(i) = n_2 \sin(r) \]
where \( n_1 \) is the refractive index of the denser medium, \( n_2 \) is the refractive index of the rarer medium, \( i \) is the angle of incidence, and \( r \) is the angle of refraction. At the critical angle, \( r = 90^\circ \).

3. **Maximum Angle of Deviation**:
- The maximum angle of deviation (Δ) during refraction when the angle of incidence is equal to the critical angle is given by:
\[ \Delta = \frac{\pi}{2} - C \]
- This means that as the angle of incidence approaches the critical angle, the angle of refraction approaches 90 degrees, leading to maximum deviation.

4. **Behavior of Deviation with Angle of Incidence**:
- If the angle of incidence is less than the critical angle (C), the angle of deviation increases as the angle of incidence increases.
- If the angle of incidence is greater than the critical angle (C), the angle of deviation decreases as the angle of incidence increases.

5. **Statements Evaluation**:
- **Statement A**: The maximum angle of deviation during refraction is \( \frac{\pi}{2} - C \) when the angle of incidence is equal to the critical angle. **(Correct)**
- **Statement B**: The maximum angle of deviation for all angles of incidence is \( \pi - 2C \) when the angle of incidence is slightly greater than C. **(Correct)**
- **Statement C**: If the angle of incidence is less than C, then the deviation increases as the angle of incidence increases. **(Correct)**
- **Statement D**: If the angle of incidence is greater than C, then the angle of deviation decreases as the angle of incidence increases. **(Correct)**

6. **Conclusion**:
- All statements (A, B, C, and D) regarding the refraction of light from a plane surface when light rays are incident in a denser medium are correct.

### Final Answer:
All statements A, B, C, and D are correct.

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