write an activity to find on which factors does the focal length of lens depend
Answers
Explanation:
we can conclude the focal length of lens depend upon the surrounding medium in which it is kept by performing simple experiment :
Material required :
Beaker, convex lens, measuring scale, water, circular lens holder, stone
Procedure :
By distant object method we can find the focal length of given lens [convex].
i) Take a beaker whose height is much greater than the focal length of the lens and fill it with water.
ii) Keep a black stone at the bottom of the vessel.
iii) Now dip the lens into water using circular lens holder such that it is at a distance which is less than or equal to focal length of the lens in air.
iv) Now see through the lens to have a view of the black stone.
v) Now increase the height of the lens till you are not able to see the stone’s image.
observation
When the lens is dipped to a height which is greater than the focal length of lens in air, we are able to see the image.
conclude :
By this experiment we can conclude that focal length of lens depends upon surrounding medium.
Answer:
the answer is:
Explanation:
- The focal length of a lens depends on the (i) radii of curvatureof its surfaces and (ii) on the index of refraction of the material the lens is made from.