Question

Which of the following would you prefer to use while reading small letters found in the dictionary?
(A) A concave mirror
(B) A concave lens
(C) A convex mirror
(D) A convex lens

Answer 1

Hint: There are different kinds of mirror and lenses available. The different kinds of lenses and different mirrors will have their applications. The image formation, convergence and divergence of rays happen differently.
We will need to see which mirror or lens magnifies the letters in order to read small letters in the dictionary.

Complete answer:
Let’s look into concave and convex mirrors and lenses:
Concave mirror:

Concave mirrors are mirrors with an inward curved reflecting surface and non-reflecting outward surface. If we are going to read the letter we need to have both surfaces of the object to be transparent to read the text.
Convex mirror:

The convex mirror cannot help our cause of reading the small letters.
If we see the convex lens the same is the case, but this time the reflecting surface is curved outward. We cannot read the text in the dictionary using a concave or a convex mirror.
It is basically because they do not possess a transmission of rays from one side to the other.
If we think about the lenses,
Convex lens:

Convex lenses are made by joining convex mirrors. They are thick at the centre and thin at the edges. These lenses are known to converge the rays. This convergence helps in reading the text in the dictionary. They are used in microscopes as well to see enlarged images of the small subject.

Concave lens:

Concave lenses look like they were made by joining two concave mirrors in symmetrically opposite fashion. They are thicker at the edges and thinner at the center. This will make the transmission of rays possible from one side to the other and can be used to see through.
But, these lenses divert the rays which means they are able to focus the rays from long distances on the retina. They will not help in reading text from the dictionary.

Therefore, To read small letters in the dictionary we use a convex lens. So, option (D) is correct.

Note :
Concave mirrors can produce both real and virtual images: they can be inverted real or upright virtual. Also, they can be in front of the mirror or behind the mirror. They can also be enlarged or diminished or of the same size as that of the given object.