A ray of light passing through the principal focus of a convex lens after refraction

Options

A. passes through the optic centre.
B. emerges parallel to the principal axis.
C. emerges without any deviation.
D. None of these

Answer

To solve the question regarding the behavior of a ray of light passing through the principal focus of a convex lens after refraction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Lens**:
- We are dealing with a convex lens. A convex lens is thicker at the center than at the edges and converges light rays that are parallel to its principal axis.

2. **Identifying the Principal Focus**:
- The principal focus (F) of a convex lens is the point where parallel rays of light converge after passing through the lens.

3. **Ray of Light Passing Through the Focus**:
- According to the question, we have a ray of light that is passing through the principal focus of the convex lens.

4. **Behavior of the Ray After Refraction**:
- When a ray of light passes through the principal focus of a convex lens, it will emerge from the lens parallel to the principal axis. This is a fundamental property of convex lenses.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the ray of light passing through the principal focus of a convex lens after refraction emerges parallel to the principal axis.

### Final Answer:
The ray of light passing through the principal focus of a convex lens after refraction emerges parallel to the principal axis.

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