Question

The lens used in a photographic camera is
(a) Concave lens
(b) Convex lens
(c) A combination of concave and convex lens
(d) A lens with convex mirror on one side and concave at the other.

Answer 1

Hint: We can easily answer this by using the definitions of concave and convex lens. If we come to know that the image formed by a convex lens is real and inverted and the image formed by a concave lens is virtual and erect then we will find that the virtual image does not actually exist.

Complete answer:
All must be familiar with photo cameras. We have seen that in our home and many functions. This is a technical gadget which is used for taking photographs.

We will consider the following diagram for understanding camera lenses.

By the diagram we clearly see that the image formed by the convex lens is real and inverted. This means that the sensors present in a convex lens implies the image like so. It consists of a lens in a box. The camera lets enough light to enter into it. After refracting the rays of light through the lens it makes it to form an image of an object AB at position A’B’.

So, the correct answer is “Option B”.

Note:
 If an object is not adjusted to the right focal length then, the image will be a little blur and not clear at all. This can also be noticed in our cell phones as well. We never use a concave lens because it will form a virtual image lens which is not needed. The rays originating from the object are divided into three parts. The first ray on the top gets refracted to below of its line. The ray that passes through the center of the lens gets refracted without deviation while the last ray changes its direction towards the making of the image.