How do you verify experimentally that the focal length of a convex lens is increased when it is kept in water?
To prove: the focal length of a convex lens can be increased when dipped in water.
Apparatus required:
A convex lens of a particular focal length.
Vessel
Water
Lens holder
Stone
Procedure:
Take a vessel such that its height is four times the focal length of the convex lens.
After putting the stone in the vessel fill the vessel with water up to a height greater than the focal length of the lens
Using the holder dip the lens into the water.
Try to observe the distance between the lens and the stone and set the distance between them such that the distance is less than or equal to the focal length of the lens.
View the stone through the lens.
Then increase the distance between the stone and the lens.
When the distance becomes greater than the focal length of the lens, the stone will not be visible when viewed through the lens.
Thus the focal length of the lens is increased when the lens is immersed in water.
To prove: the focal length of a convex lens can be increased when dipped in water.
Apparatus required:
A convex lens of a particular focal length.
Vessel
Water
Lens holder
Stone
Procedure:
Take a vessel such that its height is four times the focal length of the convex lens.
After putting the stone in the vessel fill the vessel with water up to a height greater than the focal length of the lens
Using the holder dip the lens into the water.
Try to observe the distance between the lens and the stone and set the distance between them such that the distance is less than or equal to the focal length of the lens.
View the stone through the lens.
Then increase the distance between the stone and the lens.
When the distance becomes greater than the focal length of the lens, the stone will not be visible when viewed through the lens.
Thus the focal length of the lens is increased when the lens is immersed in water.
