Question

Briefly describe an activity to find approximate focal length of a convex lens

Answer 1

To find the focal length of convex mirror and concave lens, you will need to use the mirror formula. You cannot find the focal length of convex mirror and concave lens using simple activity. The method of finding focal length of concave mirror is given below.

Fix concave mirror to mirror holder and place it on a plane surface (say a long table). Turn the face of mirror towards a distant object (may be candle).

Now adjust the screen ,candle and the mounted concave mirror so that they are all on the principal axis.

Move the screen back and forth and determine the position for the brightest clearest  image

Measure the distance between the concave mirror and the screen with a metre scale. Record your observations in observation table. 

Repeat the experiment two or three times and find the mean value of the focal length.​

You can use the same me

Answer 2

hope...it will help you