Mirror Image | General Aptitude for GATE - Mechanical Engineering PDF Download

When we look at ourselves or any object in a mirror, the way we perceive the reflection is known as a mirror image or mirror reflection. This concept is based on lateral inversion. Therefore, let’s first explore what lateral inversion means.

What is Lateral Inversion?

Lateral inversion simply means the interchange of the right side with the left side and the left side with the right side in the mirror image of the object when compared with the object. In its literal sense lateral just means “sideways” and “inversion” means “reversal of position”, so lateral inversion means a reversal of sideways.

Types of Mirror Images:

This section will make you know what kind of or type of questions is being asked in the examination.

Mirror Image of letters

We have read the definition of mirror image but here we will apply it. The case is related to a mirror image of letters and numbers. The below given example is showing the mirror image of the letter “B”. You can see that LHS has been interchanged with RHS.

Some letters do not change upon reflection. The letters which are having identical mirror images are A, H, I, M, O, T, U, V, W, X, and Y. Similarly in small letters we have i, l, o, v, w, and x that have the same mirror image as that of their original images.

(a) Mirror Image of Capital Letters:

(b) Mirror Image of Small Letters :

Mirror Image of numbers

8 is the only numeral that have the same mirror image as that of its original.

Shape Mirror Image

The point of an object near the mirror will be always near the mirror image also.

Clock-Based Mirror Images

• Rule 1: If the time is between 1: 01 to 10: 59 (i.e 11: 00) then subtract the asked time from the 11: 60
• Rule 2: If time is between 11: 01 to 12 : 59  then subtract the asked time from the 23: 60

Tips and Tricks to Solve Mirror Images Questions

Case 1: If the mirror is being placed at the top of the image
If the mirror has been placed horizontally (meaning on top of the object) then the top and bottom part in the image will be changed, while the left and right side of the image remains the same.
The mirror image of the object will be seen as follows:

Case 2: If the mirror is being placed on the right-hand side of the image.
In this case, the mirror will be placed vertically. The top and bottom parts of the placed object will remain the same, however, the left and right sides of the image will be interchanged in the mirror image.

Case 3: When the mirror is placed on the left-hand side of the image
In this case, the mirror will be placed vertically. The top and bottom part of the object remains the same, while the left and right side of the object will be interchanged in the mirror image.

Mirror Images Questions and Answers

Q1: If the mirror is placed vertically, then identify the correct mirror image of O B S T I N A T E?
Ans: (a)
Sol:
Step 1: Check the first and last letters. Here O is at rightmost and E is at leftmost. According to the lateral inversion rule they will be interchanged in the mirror image.
Step 2: Eliminate the rest which does not follow the rule. This will save your time.

Q2: Choose the correct mirror image which closely resembles the mirror image of the given image.

Ans: (b)
Sol: 
If the mirror has been put beside the given image, then the shaded part will become LHS in the mirror image because it is  RHS in the original image.

Q3: If a clock shows the time 9:15 then what will be the time shown by the mirror image?
Ans: Drawing the clock and then seeing the mirror image of each and everything will make the task cumbersome and tough, which would be time taking in the exam. So such a question can be solved by the following trick:
11 : 60 – 9 : 15 = 1 : 45

Q4: If a clock shows the time 11:15 then what will be the time shown by the mirror image?
Ans: 23 : 60 – 11 : 50 = 12 : 10.

Q5: Find the mirror image of a clock showing the time as 6 : 30?
(a) 4 : 30
(b) 5 : 30
(c) 12 : 30
(d) 10 : 30
Ans: (b)
Sol:
As the question falls into the first case so given time will be subtracted from the 11 : 60.
11 : 60 – 6 : 30 = 5 : 30.