How will you identify the three mirrors convex concave and plane mirror without touching them

CBSE 10 - Physics

Science

Asked by panwarn1234 | 02 Dec, 2020, 02:43: PM

23

The three types of mirror can either be identified by their shape or the type of image it makes of a person standing in front of it.

We will look into the mirror by going close to it:(i) If image is of same size and erect-plane mirror.(ii) If image is of bigger size and erect – concave mirror.

(iii) If image is of smaller size and erect – convex mirror.

To distinguish between a plane mirror, a concave mirror and a convex mirror without touching it, bring each mirror near to your face one by one and note the change in size of the image formed. There can be following three cases.

Case 1 : In plane mirror, if the object is upright, the image is also upright, of same size and does not change in size by moving the mirror towards or away from the face.

Case 2 : In concave mirror, if the object is upright, the image is also upright but magnified and increases in size by moving the mirror away from the face.

Case 3 : In convex mirror, if the object is upright, the image is also upright but diminished and decreases in size by moving the mirror away from the face.

Answer

Hint: Plane mirrors always produce virtual, erect images that are of the same size of the object. Convex mirrors always produce a virtual, erect and diminished image. Concave mirrors produce a virtual erect and enlarged image of the object when the object is kept very near (within the focus) of the mirror.Complete step by step answer:We can identify the three types of mirrors, that is, plane mirror, convex mirror and concave mirror by the properties of the images that they form when an object is kept near it.If we bring an object such, as a pencil, close to the mirror, we can identify the type of the mirror by observing the nature of the image of the pencil and its size.The plane mirror will form a virtual, erect image of the same size as that of the pencil. The mirror will always form a virtual, erect image regardless of the distance of the pencil from the mirror.The convex mirror will form a virtual, erect image of the pencil that is smaller in size than the actual pencil. The mirror will always form a virtual image regardless of the distance of the pencil from the mirror.If the pencil is brought very close to the mirror (within its focus), an enlarged, virtual and erect image of the pencil will be formed. If the pencil is moved away from the mirror, after a certain point (on crossing the focus), the image will not be seen on the mirror but on a screen (the image will become real, not virtual).Note: The different image properties of the mirrors form the basis for their applications. For example, concave mirrors are used as shaving mirrors since they can form a virtual, erect and enlarged image of the face, which is useful while shaving in small spaces on the face.Convex mirrors are used in side view mirrors of cars since they form a virtual and erect image always and give a wider field of view as they are curved outwards. Thus, the driver is able to view a large area of the road in the mirror.