question_answer 51)

  Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case. (a) Object is placed between device and its focus, image formed is enlarged and behind it (b) Object is placed between the focus and device, image formed is enlarged and on the same side as that of the object (c) Object is placed between infinity and device, image formed is diminished and between focus and optical centre on the same side as that of the object (d) Object is placed between infinity and device, image formed is diminished and between pole and focus, behind it

Answer:

                    (A) The spherical mirror is used as concave mirror.                 Object between F and P (b) The spherical lens is used as convex lens. Object between focus (F) and device (O) (c) The spherical lens is used as concave lens, Object between infinity and device (O) (d) The spherical mirror is used as convex mirror. Object between infinity and device (P)