5 Two convex and concave lens are in contact and having

Last updated: 6/7/2023

5 Two convex and concave lens are in contact and having focal length 12 cm and 18 cm respectively Focal length of joint lens will be a 50 cm b 45 cm c 36 cm d 18 cm 6 Two lenses are kept in contact with powers 2D and 4D The focal length of this combination will be