Question

A lens of power 5D forms an image in the same side of the object at a distance of 15cm from the
lens. If another lens of another type is kept in the same place for the same object distance how
does the image nature, position, distance and magnification of the object change due to the second lens.​

Answer 1

Using the definition of Power of a Lens, we can determine the focal length (f) of the lens. f = 1/5 = 0.2 m = 20 cm.

The lens is a CONVEX lens for TWO reasons: (a) the Power is positive; (b) the image is VIRTUAL & Magnified, which is a property of a convex lens.

Di would be NEGATIVE (2 Do) with the convention that virtual image distances are NEGATIVE.

Using the lens equation: Do = 10 cm.