# Find total magnification for a system of 2 converging lenses?

1. Apr 19, 2012

### yddet12

1. The problem statement, all variables and given/known data

There are two converging lenses. The object of the first lens (i.e. the lens on the left) is 17.5 cm to the left of the first lens, and the resulting image from the first lens is 23.33 cm to the right of the first lens.

The second lens is 40 cm to the right of the first lens. The image formed by the first lens is used as the object for this second lens, and the new image, formed by the second lens, is 42.85 cm to the right of the second lens.

Find the total magnification of the system. (i.e. magnification of the second image from the original object).

2. Relevant equations

Mtotal = M1 * M2 = (-di/do) * (-di/do)

3. The attempt at a solution

I got -1.33 for the magnification by the first lens and -2.57 for the magnification by the second lens, so the total magnification is -2.57*-1.33 = 3.42. Is this right? I'm a little unsure on this, so I wanted to make sure I was doing it right.

Thanks!

Last edited: Apr 19, 2012