The reflection of any object, character, number or any shape in the mirror is called mirror-image .
For example, when we see ourselves in the mirror, we see our mirror-image in the mirror. Observe your own mirror-image carefully, that our right side (body) is on the left side in the image and our left side is on the right in the image. It is not just with us but with the reflection of all objects, the properties of this mirror image is that the object, character, number or the left part of any shape is visible on the right side and the right part of any shape is visible in the left side. This quality is called horizontal reversal.
Whereas the image, character, number or any shape formed in the water is called the water-image . This is the quality of the water-image that appears in the water reflection is that the upper part of the object, character, number or the top of the shape will appears below and bottom of the shape appears on top. While the right or left part remains unchanged. This quality of the water image is called a vertical reversal.
There are two types of questions related to mirror-image. In First type of question it is asked that on which side of the object (i.e. right or left or top or bottom) mirror is placed. Then it is asked how the object’s image will appears by placing the mirror on that side. In the second type of question,it is asked how the object’s image will be formed. In this position, mirror is considered in front of the object, i.e. position is on the right or left side of the mirror.
The properties of the image on the left or right side of the mirror
(i) If there is a mirror on the right or left side of the object, then the upper and lower part of the object is always same in the mirror-image.
(ii) The right part of the object goes towards the left in the mirror-image and the left side of the object goes towards the right in the mirror-image.
(iii) The object’s image changes from the middle, i.e. the part from the middle to the right side will appear on the left side in the image and the left side from the middle will appear on the right side in the image.
The properties of the mirror above or below the mirror
(1) If the mirror is placed above or below the object, then the upper part of the object is shown below in the mirror and the lower part of the object is shown above the mirror.
Object: 1 ↑ ⇒ Image ↓ (mirror up or down)
If the mirror is in front of the object
In this situation, to find the mirror-image, the candidate should see the image from the back side of the page and find out that how it looks. the mirror-image will be same as if the mirror is in front of the object, if the object seen from the back page. Now we will see a mirror-image of some objects, characters, numbers and shapes as an example.
1. If the mirror is on right or left
The water-Image has the exact same position as the top or bottom of the mirror.
(i) The right and left part of the object remains unchanged.
(ii) The upper part of the object goes down in the mirror and the bottom of the object goes up in the mirror.
Now we will see some examples in line with the questions asked in the examination.
Example: When Seeing the figure below in the mirror, how will the mirror-image be formed?
Solution: (d) This position is from the position of the mirror AB. When the mirror is under the object, then the lower part of the object appears on top and upper part of the object appears on bottom. It does not affects right and left.
We have drawn a hypothetical line in the question shape so that it can be clear that which part is lower and which part is upper so that there is convenience in reversal. On the reverse of the shape we have the shape of the answer (d). Since the position of the mirror is below the object, so the shape of the option (d) will also be the water-image of the object and also the mirror-image.