Question

What kind of mirror is used in the big shopping stores to watch the activities of customers?

Answer 1

Hint: At first we need to understand why there is a need of mirror inside big shopping complexes and after understanding the need of mirror we need to match the characteristic of different mirrors so that we could find the mirror that is actually required inside a shopping complex to look over the activities of customers.

Complete answer:
Big shopping stores are inside a large complex and it is not possible to have so many employees to look over each and every counter in the complex individually. So owners have to find something by which they could look over a large place at once and in this way the manpower required would also be less. So, to attain this need, they use convex mirrors to watch the activities of the customers. Convex mirror is used as it has a large field of view, hence it allows the shopkeeper to track all the activities inside the store at once and for all.

Now for formation of image a convex mirror has two cases,
1st case - Then the object is anywhere between the pole and the infinity then the position of the image is between the pole and the focus of the mirror and the size of the object is diminished but the image is virtual and erect.
2nd case - When the object is at infinity then the image formed is behind the mirror and at the focus the image becomes highly diminished and it is virtual and erect.

Note:
We need to know the uses of mirrors and their characteristics to understand how one mirror can help in watching over activities of individuals in a shopping complex. Remember to know all the points, how the images are formed, how the mirror behaves when the object is placed at different positions etc.