(adsbygoogle = window.adsbygoogle || []).push({}); An object and a screen are fixed at a distance of 80cm apart and a convex lens forms a real image of the object on the screen. When the lens is moved along its axis a distance of 16cm, a real image of the object is again formed on the screen. Find the focal length of the lens and the magnification in each case.

m=v/u

1/u + 1/v - 1/f

I've been at this for the last 20-30 minutes and I've come no closer to the solution. I've tried letting the first distance from the lens (u1) = 2f whereby the image will be the same size.. no help.. and I've tried letting the distance between the 2 focuses of the lens=16cm.. no help.. and I've tried letting u1=xcm and u2=16+xcm but again.. no help.. I'd appreciate if someone could assist me.Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Convex Lens Question

**Physics Forums | Science Articles, Homework Help, Discussion**