Question

A student obtained a sharp inverted image of a distant tree on a screen placed in front of a concave mirror. He then removed the screen and tried to look into the mirror. He would now see:
A) A very blurred image on the wall opposite to the mirror
B) An erect and magnified image of the tree in the mirror
C) No image as the screen has been removed
D) A highly diminished inverted image of the tree at the focus of the mirror

Answer 1

Hint: A concave mirror produces a highly diminished inverted real image of a far away object at its focus. This real image can only be observed on a screen. The eyes of a person can also act as the screen in such a case since the retina inside of the eye is similar to a screen in its function.

Complete answer:
When an object is kept at a large distance away from a concave mirror, a highly diminished, inverted real image of the object is formed at the focus of the mirror. This real image can be obtained on a screen.
In this case, since the tree is at a large distance away from the concave mirror, a sharp, highly diminished, inverted, real image is formed at the focus which the student obtains upon the screen.

However, even if he removes the screen and looks into the mirror from the same position as where the screen was earlier (that is, at the focus), he will be able to see an image. This is because the eyes of the observer will act equivalent to a screen. The retina inside the eye has a similar function to a material screen.

Hence, the student will be able to see a highly diminished inverted image of the tree at the focus of the mirror.

Therefore, the correct option is,A highly diminished inverted image of the tree at the focus of the mirror.

So, the correct answer is “Option D”.

Note:
Students must note that in normal situations, the eye lens forms an inverted real image of all objects around us that we see, on the retinal screen. However, this image is converted back to the erect form by the brain and hence, we thus see the final erect image and correct orientations of the objects around us as they actually are. The eye lens is a convex lens that changes its focus constantly such that the inverted images of the objects that we see are correctly formed on the retinal screen. So, students must not think that, if the screen is removed, the student will not be able to see the image in this case absolutely since we have an inbuilt screen in the form of a retina inside our eyes.