The correct option is B
Hint: Consider snells law and Critical angle
Critical angle is given as,
Where, is the refractive index.
In order to describe the relation between the angle of incidence and reflection snells law is used.
Where is the angle of incidence and is the angle of reflection.
Explanation for correct answer:
Step 1: Information required
Critical angle is given as,
Where, is the refractive index.
In order to describe the relation between the angle of incidence and reflection snells law is used.
Here, is angle of incidence
is the angle of reflection.
Angle of prism
Refractive index
Step 2: Calculate the angle of reflection,
The angle of the prism is the sum of reflection and critical angle.
Then,
Substitute the value of critical angle and angle of prism in the above equation
So, the angle of reflection is .
Step 3: Calculate angle of incidence,
Consider snells law,
Hence the angle of incidence is .