00:01
In this question we are given that there is a transparent material here which is silicon nitrite and there is a ray incident here at an angle 60 degree and this point name is a.
00:22
So it is going to hit from here to here.
00:24
This is the angle of reflection r.
00:28
This is point b.
00:31
Now what we need to do is in the part a we have to actually find the angle of reflection r.
00:39
Which we can see from the diagram.
00:41
So that is very simple.
00:42
I think everyone can do that.
00:44
It is, as we know that, there is air here, whose refractive index we know is one.
00:52
And here it is silicon nitrite whose refractive index is given to us as two.
00:57
So now we can apply snells law here, which says 1 times of sine 60 is equal to 2 times of sine r.
01:09
So which implies sine 60, we know it is root 3.
01:13
2 is equal to 2 times of sine r.
01:17
So the value of r can be calculated from here, which is sine inverse of root 3 by 4, which if you solve will come out to be approximately equal to 25 .66 degrees.
01:35
So now in the second part of the question, we need to find this angle of incidence here.
01:42
So we can see in this triangle, this is 90 degree, this is r, this is i...