A ray of light incident normally on one of the faces of a right angle prism is found to be totally reflected as shown in figure. What is the minimum value of the refractive index of the material of the prism?

Question

A ray of light incident normally on one of the faces of a right angle prism is found to be totally reflected as shown in figure. What is the minimum value of the refractive index of the material of the prism? (A)  √2  (B)  √(3/2)  (C)  (4/3)  (D) None of these

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/ef6da0db30164f6628d36a51786d194d-.png" /> For total internal reflection θ ge C Where C is the critical angle ∴ sin θ ge sin C sin θ (1/4) μ ge (1/ sin 45°) μ ge √2

Q. A ray of light incident normally on one of the faces of a right angle prism is found to be totally reflected as shown in figure. What is the minimum value of the refractive index of the material of the prism?

$2$

$\frac{3}{2}$

$\frac{4}{3}$

None of these

For total internal reflection
$θ \geq C$
Where $C$ is the critical angle
$∴ sin θ \geq sin C$
$sin θ \frac{1}{4} μ \geq \frac{1}{s i n 4 5 ^{\circ}}$
$μ \geq 2$

Q. A ray of light incident normally on one of the faces of a right angle prism is found to be totally reflected as shown in figure. What is the minimum value of the refractive index of the material of the prism?

2​

23​​

34​

None of these

For total internal reflection θ≥C Where C is the critical angle ∴sinθ≥sinC sinθ41​μ≥sin45∘1​ μ≥2​

$2$

$\frac{3}{2}$

$\frac{4}{3}$

For total internal reflection
$θ \geq C$
Where $C$ is the critical angle
$∴ sin θ \geq sin C$
$sin θ \frac{1}{4} μ \geq \frac{1}{s i n 4 5 ^{\circ}}$
$μ \geq 2$