Question

Find the angle of incidence at face ab so that the emergent ray grazes along the face ac

Answer 1

Answer:

Let, incident ray passes through face ab, as an incident ray is that ray which when passes through the surface, either it is reflected or refracted.

Now, when incidence ray is reflected, when medium does not change

Angle of incidence = Angle of Reflection

When , we draw a normal at the point where incident ray strikes the surface.

Now, when incident ray strikes the surface a b, is refracted through the surface, that is when medium changes, is emerged through the surface ac,

In this case when there are two mediums, we will use Snell's law to determine, the relation between incident ray, refracted ray and emergent ray,

we get When we compare rays in medium 1 and medium 2

$\frac{sin d}{sin r}=\frac{sin e}{sin r}\\\\ d=e$

Angle of incidence ≠Angle of refraction

Angle of incidence(d)=Angle made by emergent ray(e)