Question

define focal length of a convex lens in an experiment to determine the focal length of a convex lens the image of a distant object formed by a lens is obtained on a screen what is the nature of the image how can the focal length of a convex lens be estimate

Answer 1

hlo mate




1. Fix the convex lens on the lens holder or stand and place it place it on the table near an open window of the laboratory.

2. Locate a distant tree/building from the open glass window (if an open window is not available then obtain the image of the window itself on the screen.

3. Place the screen behind the convex lens.

4. Adjust the position of the convex lens and the screen so that a sharp, inverted and diminished image of a distant object is formed clearly on the screen.

5. Note the positions of the screen and the convex lens stand with the help of measuring scale.

6. Find the distance between the optical centre of the lens and the screen. This distance is equal to the focal length of the convex lens. Record the the focal length.

7. Repeat the experiment a few times by changing the positions of the convex lens stand and note the corresponding changed position of the screen.

8. Calculate the mean value of the focal length.

hope it helps u