The focal lengths of the two lenses are 20cm and -20cm respectively. Mention the types of these two lenses. Out of these two lenses, which one forms a virtual and magnified image when an object is kept 16cm away from the lens? Explain it by drawing a scaled ray diagram.
Arpit Sundas
·
1 year ago
Solution
Here,
The the lens with the focal length 20 cm is a convex lens as its focus is real.
Ans, the lens with focal length -20 cm is a concave lens as its focus is virtual.
The lens with focal length 20cm i.e. a convex lens forms a virtual and magnified image when the object is kept 16 cm from the lens. When a object is placed between focus(F) and optical center(O) of a convex lens it forms a virtual and magnified image.
Here, the distance of object is 16cm i.e. between F and O. So, a convex mirror can form virtual and magnified image with given condition.
Ray diagram:
