3. We are given a convex lens of focal length 20 cm. Draw ray diagrams to show the nature, size and position of the image formed when the object is kept at a distance of?
(a) 55 cm?????????????????? (b) 35 cm??????????????????? (c) 15 cm?
from the lens.?
[?Note: For drawing ray diagrams, use an appropriate scale.]?

4. We are given a concave lens of focal length 15 cm. Draw a ray diagram to show the nature, size and position of the image formed when the object is kept at a distance of?
(a) 30 cm??????????????? (b) 15 cm?????????????????? (c) 10 cm?
from the lens.?
[?Note: For drawing ray diagrams, use an appropriate scale.]