The concave mirrors are used in: A. Reflecting telescope B. Magic lanterns C. Cinema projectors D. All of these
Hint: A reflective surface that is curved inside and away from the light source. Concave mirrors are reflecting to affect the inward of focal point. It shows different image types depend on the distance of the object from the mirror. A reflecting surface away from the incident light is called a concave mirror.
Complete step-by-step solution: Concave mirrors are used in many ways, from those we are looking into some of the objects which were used by them and mentioned in the question. Reflecting telescope: Reflecting telescope used by astronomers to see clearly far away objects in space. The first mirror in the reflecting telescope is wide and reflects the image in another mirror. Thus the reflecting telescope has a concave mirror. Magic lanterns: Magic lanterns are slide projectors used to amuse and entertain the audiences. The magic lantern uses a concave mirror in back light to source to direct light through small rectangular glass. Thus we noticed that magic lanterns use concave mirrors. Cinema projectors: project a beam of light outward through which reflect the projector, and light rays spread over the distance and produce large images. Thus the cinema projectors also used concave mirrors.
Note: Concave mirrors are used in our daily life such as shaving mirrors, head mirrors and headlights and so on… from the question we have concluded that all the given options are correct and those are made of concave mirrors. Thus the correct option is all of these from the given options.