Question

Where is an image located if a concave mirror of focal length f forms an image of the moon?

- At the mirror’s surface.

- At a distance behind the mirror equal to the distance of the moon in front of the mirror

- Almost exactly a distance f behind the mirror.

- Almost exactly a distance f in front of the mirror.

Answer 1

Light rays coming from moon can be considered that light rays are coming from infinity because the distance between the concave mirror and the moon is very very large. So when a light ray comes from the infinity it always passes from the focus of rhe concave mirror. And the focus is in front of the mirror. As shown in the diagram the image formed will be very very small in nature and it will be almost at the focus which is in front of the mirror hence option 4 is the correct answer.

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