Question

How to find out focal length of a convex lens by displacement method theory?

Answer 1

I hope this answer is helpful for you

Answer 2

Answer: To find out focal length of a convex lens by displacement method theory we need a convex lens, screen, an object and scale to measure

Explanation:

Place the convex lens on the scale with object at one end and screen to capture the image at the other end.

Place the lens close to the object and note the distance between them when a clean image is formed on the screen and name it d1. Then take the lens close to the screen till a clean image is formed again and then name the distance as  d2. Subtract d1 from d2 you will get d the distance between the lens

Let D be the distance between the object and the screen.

Use slope formula = (D.D-d.d)/D

Focus length formula f= (D.D.-d.d)/4D

That is                          f= slope/4.