# two mirriors are inclined to eachother at angle 70 . a ray which is incident on 1st mirrior at an angle x, comes out of the combination after reflection from the mirrirs , parellel to the 1st mirror . find angle x.

Grade:12th pass

## 2 Answers

Shivam Chopra
45 Points
7 years ago
The answer is 55 degree.
When the light strikes 1st mirror at angle x, it will get reflected at same angle.
Now, if we want that the final reflected line should be parallel to 1st mirror, then, the light ereflected from the 1st mirror should fall at 2nd mirror at same angle i.e. x.
So, the angle of reflection from 1st miorror = angle of incidence on 2nd mirror = x.
Now, in the triangle formed, 70 + x + x = 180.
So, x comes to be 55 degree.
( You can make a diagram for this phenomenon. You will also find that the reflected ray from 1st mirror is parallel to the ground or horizontal )
Please approve it if you like.
maitreyee jagannath
36 Points
7 years ago
well the ans in the book is 50 degree ..

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