Question

The curved surface of a shining spoon can be considered as a …
(A)Curved mirror
(B)Plane mirror
(C)Concave mirror only
(D)None

Answer 1

Hint: A spoon is curved shaped and shiny, which means it reflects light from its surface to form images on it. The shiner the spoon, the more distinct is the reflection and the clearer the image is formed. We can test the surface of the spoon by doing a small activity where we observe the image formation of the spoon at different distances.

Complete step by step answer:
Firstly, we take the part of the spoon which is bent inwards. By doing a small activity and observing the results, we can easily deduce the type of mirror that a spoon acts as.
Holding the spoon in one place, if we try to approach the spoon and get closer and closer to the spoon, we will see that our image on the curved surface of the spoon gets larger and larger until highly magnified. Again if we go away from the spoon, the image becomes smaller and smaller until it diminishes in size.
These are the conditions for the image formation of a concave mirror. So the surface of the spoon that is bent inwards acts like a concave mirror.
Again, if we turn the spoon to the bulged out part, and try to observe the image formation, we can deduce the type of mirror it acts like. If we fix the position of the spoon facing the bulged out part of the curve, no matter what the distance, the image formed is always a diminished one. A diminished image is formed no matter where the object is only and only if the mirror is convex.
So, we can conclude that the bulged out part of the spoon acts like a convex mirror.
Hence, by doing a small experiment we know that the bulged out part of the spoon acts like a convex mirror and the part of the spoon that is bent inwards acts like a convex mirror. Thus, we can say that the curved spoon entirely behaves like a curved mirror, one side diverging and the other side converging.

So, the correct answer is “Option A”.

Additional Information: Concave and convex mirrors have different positions and dimensions of image for different positions of object, same is the case with lenses. A concave mirror is also called a converging mirror and a convex mirror is also called a diverging mirror. Both the types of mirrors together are called curved mirrors.

Note: We need to understand the image formation of both concave and convex mirrors to understand the solution of the problem. Using ray optics, we can easily derive the positions of images when an object is placed at different positions and thereby name the type of mirror that shows such a characteristic.