Two Converging Lense Questions Please Help

[JM2107]

For a lens of focal length f, what value of the distance between the object and the lens[D0] would give an image with a magnification of one?

Is it possible to obtain a non-inverted image with a converging spherical lens? Explain please?

Any response would be greatly appreciated, and I would like to thank anyone for their response to this thread in advance.

[arcnets]

Hi JM2107,
to answer questions like this, you could use use 2 methods:
1) Draw 3 rays, remembering that...
... focal ray becomes parallel ray
... parallel ray becomes focal ray
... central ray is not refracted
2) Use the Law of lenses: 1/o + 1/i = 1/f
where
o = distance of object from lens
i = distance of image from lens
f = focal length

Got it? [;)]

[Claude Bile]

It is not possible to obtain a non inverted image using a single converging lens. It is therefore not possible to obtain a magnification of 1, though it is possible to obtain a magnification of -1. (Inverted images have a negative magnification by convention).

The reason for this is purely geometrical. Arcnets outlined a standard graphical method of seeing why this is.

[arcnets]

Originally posted by Claude Bile
It is not possible to obtain a non inverted image using a single converging lens.
R u sure? How about a virtual image? See here...

www.lightlink.com/sergey/java/java/clens/

[Meninger]

Here's the answer:

Yes, it is possible to obtain a non-inverted image with a converging lens. As long as the object is between the focal length point and the lens it is possible. Of course this would be a virtual image and the image would be magnified.


m=-d(image)/d(object)

If m=1 than we have an equation where we can put d (object) = - d (image). Since 1/f = 1/d (object) + 1/d (image) and since d (object) = - d (image), therefore 1/f = 0

So there is no distance that would give a magnification of one.