Two light rays incident parallel to each other on an optical boundary will undergo the same refraction.

Options

A. `"True"`
B. False
C. data is not given
D. none of the above

Explanation

To solve the question, "Two light rays incident parallel to each other on an optical boundary will undergo the same refraction," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have two light rays that are incident parallel to each other on an optical boundary separating two media with different refractive indices, \( N_1 \) and \( N_2 \).

2. **Identifying the Normal**:
- Draw a normal line perpendicular to the optical boundary at the point of incidence. This normal line will help us measure the angles of incidence and refraction.

3. **Defining Angles of Incidence**:
- Let the angle of incidence for both rays be \( i_1 \). Since the rays are parallel, they will make the same angle with the normal.

4. **Applying Snell's Law**:
- According to Snell's Law, the relationship between the angles of incidence and refraction is given by:
\[ N_1 \sin(i_1) = N_2 \sin(r_1) \]
- Here, \( r_1 \) is the angle of refraction for the first ray.

5. **Applying Snell's Law to the Second Ray**:
- For the second ray, we can similarly apply Snell's Law:
\[ N_1 \sin(i_1) = N_2 \sin(r_2) \]
- Here, \( r_2 \) is the angle of refraction for the second ray.

6. **Equating the Two Equations**:
- Since both rays have the same angle of incidence \( i_1 \), we can equate the two equations:
\[ N_2 \sin(r_1) = N_2 \sin(r_2) \]

7. **Cancelling Out the Refractive Index**:
- Assuming \( N_2 \) is not zero, we can divide both sides by \( N_2 \):
\[ \sin(r_1) = \sin(r_2) \]

8. **Concluding the Angles of Refraction**:
- Since the sine function is equal, we can conclude that:
\[ r_1 = r_2 \]
- Therefore, both rays undergo the same angle of refraction.

9. **Final Conclusion**:
- Since both rays are refracted at the same angle, they remain parallel after refraction. Thus, the statement is true.

### Final Answer:
The statement "Two light rays incident parallel to each other on an optical boundary will undergo the same refraction" is **True**.