Which one of the following is the use of concave lens? a) magnifying glass b) optical instruments. c) in theatre spotlights d) all of the above

A concave lens is used in optical instruments. In other mentioned options, a concave lens is not used.

Uses

1. A concave lens is used by the manufactures of binoculars and telescopes
2. Opticians use concave lenses to correct near-sightedness also called myopia.
3. Camera manufacturers use combinations of concave and convex lenses to improve the quality of photographs.
4. Concave lenses are used on flashlights to magnify the light produced by the bulb.
5. Lasers (CD, DVD players for example).