Prove a lens must always be converging if

In summary, for an upright, enlarged image to be produced by a single lens, the lens must always be converging. This can be proven by drawing lens ray diagrams, as a concave lens will always produce a virtual and reduced image.
  • #1
jones268
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Prove a lens must always be converging if...

Consider a single lens with the object on the left side. Prove that for an upright, enlarged image that the lens must always be converging. I'm assuming my professor wants this to be mathematically proven, but I have no idea how to do so...HELP! I don't even know where to begin with this question
 
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  • #2


Well, conceptually, a concave lens will ALWAYS produce an image that is virtual and reduced in size. So, if you want an enlarged image, your lens NEEDS to be converging - there are no other options.

You could prove this by drawing lens ray diagrams. If you haven't learned how to draw those, they're pretty simple! Here's something that might be helpful :
http://www.physicsclassroom.com/class/refrn/u14l5da.cfm
 

Related to Prove a lens must always be converging if

1. What is a converging lens?

A converging lens is a type of lens that is thicker in the middle and thinner at the edges. This shape causes light rays to bend or converge towards a focal point after passing through the lens, resulting in an image that is magnified and inverted.

2. Why must a lens always be converging?

A lens must always be converging because of its shape and the way light interacts with it. The curvature of the lens causes light rays to bend towards a focal point, and this bending is necessary for the lens to create a magnified image. If a lens were not converging, the light rays would either not bend at all or would bend away from each other, resulting in a distorted or blurry image.

3. Can a lens be both converging and diverging?

No, a lens cannot be both converging and diverging. These two types of lenses have opposite shapes and properties. A converging lens has a convex shape and causes light to converge, while a diverging lens has a concave shape and causes light to diverge. It is not possible for a lens to have both of these shapes at the same time.

4. Is a converging lens always positive?

Yes, a converging lens is always positive. The term "positive" refers to the focal length of the lens, which is the distance between the lens and its focal point. A converging lens always has a positive focal length, meaning that the focal point is located on the opposite side of the lens from where the light enters.

5. How is a converging lens different from a diverging lens?

A converging lens is different from a diverging lens in its shape and the way it affects light. Converging lenses have a convex shape and cause light to converge towards a focal point, resulting in a magnified and inverted image. Diverging lenses have a concave shape and cause light to diverge, resulting in a smaller and upright image. Additionally, the focal lengths of these two types of lenses have opposite signs, with converging lenses having a positive focal length and diverging lenses having a negative focal length.

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