Discuss the below:
Q: "A magnifying glass is a single convex lens with a focal length of f = +11.0 cm. (Assume the person using the magnifying glass has a near point of 25 cm and the magnifying glass is directly in front of the person's eyes.)
(a) What is the angular magnification when this lens forms a (virtual) image at -infinity. (I've done this one. The answer is 2.27. But I can't figure out how to do the others.)
(b) How far from the object should the lens be held?
(c) What is the angular magnification when this lens forms a (virtual) image at the person's near point?
(d) How far from the object should the lens be held in this case?