Question

what is the combination of i)two convex lenses,ii)two concave lenses and state their uses

Answer 1

Answer:

Explanation: When the convex and concave lenses are glued together to correct the fact that the convex lens will focus different colours of light at different points, thus leaving a “halo” around the image. The problem is known a chromatic aberration, and the stuck together lens is called an achromatic lens