A point object O is placed midway between on the common axis of two concave mirrors of equal focal length. If the final image is formed at the position of the object, the separation between two mirrors is ........ . Focal length of mirrors is f. HINT:- A situation is depicted n the figure [ Note : A another possible situation for which object and its image coincide is when distance between mirrors is 4f ] .

A point object O is placed midway between on the common axis of two co

1.	A point object O is placed midway between on the common axis of two concave mirrors of equal focal length. If the final image is formed at the position of the object, the separation between two mirrors is ........ . Focal length of mirrors is f. HINT:- A situation is depicted n the figure [ Note : A another possible situation for which object and its image coincide is when distance between mirrors is 4f ] .
Answer» f 2f `3/2f` `1/2f` Solution :It is clear from the defination of focal POINT that when object is placed on focal point, ray incident on mirror from object becomes parallel to axis of mirror after reflection. `therefore` In FIGURE position of object is O and position of image is O. must be on the focal point on axis of CONCAVE mirror. `therefore`DISTANCE between both mirror = 2f Note : Similarly if object and image O. are on the centre of curvature distance between mirrors = 4f.

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