Question

For the following question, draw a ray diagram for each lens draw a careful and accurate ray diagram of this image (from lens 1) as an object (for lens 2) forming an image through the second lens. Finally, draw a careful and accurate ray diagram of the entire situation, including both lenses and all images.

An object 5 cm high is located 75 cm from a converging lens (X₁ = 75 cm) of focal length f₁ = 50 cm. A second converging lens of focal length f₂ is located 200 cm from the first lens (X₂ = 200 cm). An image of the object is to be formed on a screen 200 cm from the second lens (X₃ = 200 cm).

What must be the focal length f₂ of the second lens so that the final image clearly appears on the screen?

Answer 1

Firstźmage e I 1. ok- I 7san 2com -2ooc C-150 soch dol ==75cm, fi = 50cm, = 50cm, di 1=2 From lens Formulation dal dol dž 1 1 det dil so - --> 1 1 1 58 >> -75 ť 75 = j 52 -) = =) dil 1 150 Iso um Now doz = -50cm d²2=200 cm, f2 = ? 1 dź2 1 doo = 1 fa 1 200 ㅗ = -50 14 -) 11 / 1 200 1 + 11 1 l = f₂ = you 50