# Problem: Explain why you cannot measure the focal length directly for a diverging lens. Using no more than four sentences, explain why the technique of placing the diverging lens touching another converging lens with the light reaching the converging lens first, allows you to determine the focal length of the diverging lens.

###### FREE Expert Solution

The lens maker equation:

$\overline{)\frac{\mathbf{1}}{{\mathbf{s}}_{\mathbf{o}}}{\mathbf{+}}\frac{\mathbf{1}}{{\mathbf{s}}_{\mathbf{i}}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{f}}}$

f is the focal length, si is the image distance, and so is the object distance.

###### Problem Details

Explain why you cannot measure the focal length directly for a diverging lens. Using no more than four sentences, explain why the technique of placing the diverging lens touching another converging lens with the light reaching the converging lens first, allows you to determine the focal length of the diverging lens.

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Thin Lens And Lens Maker Equations concept. You can view video lessons to learn Thin Lens And Lens Maker Equations. Or if you need more Thin Lens And Lens Maker Equations practice, you can also practice Thin Lens And Lens Maker Equations practice problems.