Question

how do you find the focal length of a lens experimentally?​

Answer 1

Answer:

Using the formula f=uv/u+v

Explanation:

Here,

F is focal length

U is the distance between the object and the lens

V is the distance of the image (screen) from the lens

Answer 2

Answer:

i) Place the convex lens on a 'V' stand. . ii) Light a candle and take it far away from the lens along the principal axis. iii) Adjust the screen on the other side of the lens to get a clear image on it. iv) Measure the distance between the 'V' stand and the screen which gives a rough idea of focal length of the lens.