- #1

leolaw

- 85

- 1

A bright object is placed on one sid eof a converging lens of focal length f, and a white screen for viewing the image is on the opposite side. The distance [tex]d_T = d_i + d_0 [/tex] between the object and the screen is kept fixed, but the lens can be moved.

Show that if [tex]d_t > 4f[/tex] , there will be two positions where the lens can be placed and a sharp image can be produced on the screen.

And if [tex]d_t < 4f [/tex], no lens position where a shakrp image is formed.

Also determine a formula for the distance b/w the two lens position,and the ratio of the image sizes.

the attachement is the work that i was trying figure out how to do it. but i don't seem to know how to tackle this problem

Show that if [tex]d_t > 4f[/tex] , there will be two positions where the lens can be placed and a sharp image can be produced on the screen.

And if [tex]d_t < 4f [/tex], no lens position where a shakrp image is formed.

Also determine a formula for the distance b/w the two lens position,and the ratio of the image sizes.

the attachement is the work that i was trying figure out how to do it. but i don't seem to know how to tackle this problem