- #1
toolcake
- 3
- 0
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
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