The focal length of the lens is 20 cm. The image should be at 60 cm from the lens.
Given a plant placed 6 squares distant from a convex lens. Since the refracted rays are converging the given lens is a convex lens.
Here each square is 5 cm along the horizontal direction.
The ray from the top of the plant pass through the lens and cross the principal axis at a distance 4 squares from the lens.
Hence the focal length of the lens, f = 4 x 5 = 20 cm.
We have the lens formula for convex lens.
i.e., 1/f=1/v+1/u ,
where v is the distance of real image from the center of the lens, u is the distance of the object from the center of the lens and f the focal length of the lens.
Here, u = 6 x 5 = 30 cm
So in order to find where the real image is produced,
we have 1/v = 1/f - 1/u
Therefore, v = uf /u-f = 30 x 20 / 30-20 = 60 cm.
Thus the real image is formed at a distance of 60 cm from the center of the lens.
Your question was incomplete. Please check below the full content.
Figure 1 shows a small plant near a thin lens. The ray shown is one of the principal rays for the lens. Each square is 5.0 cm along the horizontal direction, but the vertical direction is not to the same scale. Use Information from the diagram to answer the following questions. What is the focal length of the lens? Calculate where the image should be.
Find more about the lens formula at brainly.com/question/2098689
#SPJ4