lenses, still stuck!

I need to calculate the magnification, m of an objective lens, so I can then x it by the eyepiece value for M to get the total magnification.

I need v/u (v is dist from lens to image; u is dist of object to lens)

I'm using 1/f = 1/v+1/u rearranged for 1/v.

That's: 1/v = 1/f - 1/u. I think?

The object is 26mm away from the lens; the focal length is 25mm.

I keep getting v = 650mm

Any ideas where i'm going wrong please?

Thanks.

1. 👍 0
2. 👎 0
3. 👁 93
1. The procedurre you need to follow for the total magnification of a compound microscope, which is what you are talking about, is described here:
http://library.thinkquest.org/C003776/ingles/print/microscope.htm

You need to have a specified "barrel length" for the microscope (which is the separation of the lenses) in order to calculate objective magnification. The objective lens forms an intermediate image in front of the eyepiece, and the eyepiece forms an image of the intermediate image 25 cm away.

1. 👍 0
2. 👎 0
posted by drwls
2. Thanks drwls, for that. However, the question acually asks me 2 things: the total M; and to find the length of the microscope! The questioner clearly thinks I have enough info to go on from what I've given above.

Charlie

1. 👍 0
2. 👎 0
posted by charlie

Similar Questions

1. Math/Biology

8c) The scanning objective lens (4x) of a microscope has a diameter of field of 6.0 mm and a total magnification of 40x. The high power objective lens has a total magnification of 400x. Estimate the diameter of field of view of

asked by Anonymous on May 11, 2016
2. objective and eyepiece lens

What is the approximate magnification of a compound microscope with objective and eyepiece focal lengths of 0.3 cm and 3.6 cm, respectively, and a separation between lenses of 20 cm? The answer is 460. I tried finding the

asked by katherine on May 22, 2009
3. physics, lenses

I need to calculate the magnification, m of an objective lens, so I can then x it by the eyepiece value for M to get the total magnification. I need v/u (v is dist from lens to image; u is dist of object to lens) I'm using 1/f =

asked by Anonymous on March 23, 2009
4. Physics

A simple camera telephoto lens consists of two lenses. The objective lens has a focal length f1 = +41.7 cm. Precisely 36.1 cm behind this lens is a concave lens with a focal length f2 = -13.9 cm. The object to be photographed is

asked by Rudi on September 20, 2010
5. Physics ( optics)

A simple camera telephoto lens consists of two lenses. The objective lens has a focal length f1 = +41.7 cm. Precisely 36.1 cm behind this lens is a concave lens with a focal length f2 = -13.9 cm. The object to be photographed is

asked by Rudi on September 17, 2010
6. Physics

1. A photographer uses a camera lens with focal length of 50.0 mm to photograph a tree that is 4.60 m tall. She wishes to fill her 24.0-mm slide with the tree. (a) How far from the lens should the film be? 1/o + 1/24 = 1/50 600 +

asked by Dylan on December 1, 2016
7. Science

The human egg cell above is magnified using a 10´ ocular lens and a 40´ high power objective lens. (a) Calculate the overall magnification. (b) If the field of view at high-power magnification is 400 mm, calculate the size of

asked by HELP ASAP on May 12, 2016
8. bio

The human egg cell above is magnified using a 10´ ocular lens and a 40´ high power objective lens. (a) Calculate the overall magnification. (b) If the field of view at high-power magnification is 400 mm, calculate the size of

asked by alexandra on January 7, 2017
9. Physics

The human egg cell above is magnified using a 10´ ocular lens and a 40´ high power objective lens. (a) Calculate the overall magnification. (b) If the field of view at high-power magnification is 400 mm, calculate the size of

asked by HELP ASAP on May 10, 2016
10. Physics

The human egg cell above is magnified using a 10´ ocular lens and a 40´ high power objective lens. (a) Calculate the overall magnification. (b) If the field of view at high-power magnification is 400 mm, calculate the size of