Mirrors & Lenses: Understanding Virtual and Real Images

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A diverging lens can indeed only produce a virtual image, making the first statement true. The second statement is false; parallel rays striking a concave mirror focus at the focal point, which is half the radius, not at R. The third statement is also false; an object placed beyond the focal length of a converging lens can produce either a real or virtual image depending on its distance from the lens. Lastly, the fourth statement is true; to reduce the size of an image projected on a screen, a lens with a longer focal length is required. Understanding these concepts is crucial for mastering optics.
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Homework Statement



True or False
1. A single diverging lens can only make a virtual image.
2. When parallel rays strike a concave spherical mirror with radius R they are focussed through a point R from the mirror.
3. An object placed at distance greater than the focal length of a converging lens will always make a real inverted image.
4. If a projector makes a perfect image on a screen, but the image is too large, you need a lens with a greater focal length.



2. The attempt at a solution

I thought all statements were False, but that was incorrect.
 
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pearlz4eva said:

Homework Statement



True or False
1. A single diverging lens can only make a virtual image.
2. When parallel rays strike a concave spherical mirror with radius R they are focussed through a point R from the mirror.
3. An object placed at distance greater than the focal length of a converging lens will always make a real inverted image.
4. If a projector makes a perfect image on a screen, but the image is too large, you need a lens with a greater focal length.



2. The attempt at a solution

I thought all statements were False, but that was incorrect.

Welcome to the PF.

What is your reasoning on each? Why do you think each is false? If you show us your work, we can better help you understand.
 
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