Question

If the image formed by a lens for all positions of the object in front of it is always virtual, erect and diminished, state the type of the lens. Draw a ray diagram in support of your answer. If the numerical value of focal length of such a lens is 20 cm, Find its power in new cartesian sign conventions.

Answer 1

Concave lens because it forms all images virtual erect diminished

Power will be negative as images is formed on negative