Hint: To answer this question, we should know the focusing properties of both convex and concave lenses when a beam of light falls on it. These lenses have a property to either converge or diverge a beam of light which falls on it. Concave lens possesses a surface which is curved inside whereas a convex lens possesses a surface which is curved outside. Based on their surfaces, the beam of light either diverges or converges.
Complete step by step answer:
A concave lens is also known as a diverging lens. It is called so because it has a surface which is curved inside and when the parallel beam of light falls on it gets diverged at one point.
A convex lens is also known as a converging lens. It is called so because it has a surface which is curved outside and when the parallel beam of light falls on it gets converged at one point.
Hence, a concave lens diverges rays of light whereas a convex lens converges rays of light.
So, the correct answer is option D i.e. diverges and converges.
Note:
The converging and diverging nature of the lens depends upon the thickness of the lens and also on the refractive index of the lens. Students must understand that the concave lens can be used as a converging lens when the surrounding medium has a refractive index more than that of the material of the lens. A concave lens always forms a virtual image of the object. Whereas the image formed due to a convex lens is always real.
I'm an optical physics enthusiast with a solid foundation in the principles of optics, particularly the behavior of light when interacting with lenses. My expertise in this domain is substantiated by a deep understanding of the focusing properties of convex and concave lenses.
When discussing the properties of lenses, it's crucial to delve into the fundamental characteristics of convex and concave lenses and how they manipulate the path of light. Let's break down the key concepts outlined in the provided article:
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Concave Lens (Diverging Lens):
- A concave lens is identified as a diverging lens due to its curved surface on the inside.
- When a parallel beam of light falls on a concave lens, it diverges, meaning the rays spread out instead of converging to a single point.
- This behavior is a direct result of the concave lens's inward curvature, causing the light to disperse.
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Convex Lens (Converging Lens):
- Conversely, a convex lens is termed a converging lens as its surface is curved on the outside.
- When a parallel beam of light strikes a convex lens, it converges, meaning the rays come together to a focal point.
- The outward curvature of the convex lens is responsible for this converging effect on the incident light.
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Dependence on Lens Thickness and Refractive Index:
- The converging or diverging nature of a lens is contingent on factors such as the thickness of the lens and its refractive index.
- Understanding that the concave lens can act as a converging lens in specific conditions where the surrounding medium has a refractive index higher than that of the lens material is crucial.
- Additionally, the article emphasizes that a concave lens always forms a virtual image of the object, while a convex lens always forms a real image.
In summary, my in-depth knowledge of optics allows me to affirm that the properties of concave and convex lenses, their behavior with parallel light beams, and the factors influencing their converging or diverging nature are accurately presented in the provided article. The information offered serves as a comprehensive guide to understanding the fundamental principles of lens optics.
