The correct option is **B. It focuses parallel light rays to a single point known as the focal point.** ### Detailed Explanation: 1. **Understanding Convex Lenses:** - A convex lens is thicker in the middle than at the edges. It is also known as a converging lens because it has the ability to bend light rays that are parallel to its principal axis inward, towards a single point. 2. **Focal Point:** - The point where these parallel light rays converge is called the **focal point**. The distance from the center of the lens to the focal point is known as the **focal length**. This property is crucial in optical instruments like cameras, microscopes, and eyeglasses, where focusing light is essential for forming clear images. 3. **How Light Rays Interact with a Convex Lens:** - When parallel rays of light (such as those coming from a distant object) strike a convex lens, they are refracted (bent) as they pass through the lens. The shape of the lens causes these rays to converge at the focal point on the opposite side of the lens. This is a fundamental principle of optics and is described by the lens maker's equation. 4. **Ray Diagrams:** - A ray diagram can help visualize this process: - Draw a horizontal line representing the principal axis. - Mark the convex lens in the center, showing its curvature. - Draw parallel rays coming from the left towards the lens. - After passing through the lens, these rays should converge at a point on the right side of the lens, indicating the focal point. ### Why Other Options Are Incorrect: - **Option A: It diverges light rays that are incident on it, causing them to spread apart.** - This statement describes the function of a **concave lens**, not a convex lens. A concave lens causes parallel light rays to diverge, spreading them apart rather than converging them. - **Option C: It reflects light to produce an image at a distance.** - This statement is incorrect because convex lenses do not reflect light; they refract it. Reflection is a property of mirrors, not lenses. Convex lenses focus light through refraction, not reflection. - **Option D: It has a uniform thickness and does not alter the path of light rays.** - This statement is misleading. A convex lens is not of uniform thickness; it is thicker in the center than at the edges. Moreover, it does alter the path of light rays by bending them towards the focal point. ### Common Pitfalls: - Confusing convex lenses with concave lenses is a common mistake. Remember that convex lenses converge light, while concave lenses diverge light. - Misunderstanding the concept of focal length and focal point can lead to errors in calculations and ray diagrams. ### Revision Summary: - A convex lens focuses parallel light rays to a single point known as the focal point. - The focal point is crucial for forming clear images in optical instruments. - Convex lenses are thicker in the middle and bend light rays inward. - Remember the distinction between convex (converging) and concave (diverging) lenses.