A glass prism of refractive index 1.5 is immersed in water (μ=4 / 3). Light beam incident normally on the face A B is totally reflected to reach the face B C if

Question

A glass prism of refractive index 1.5 is immersed in water (μ=4 / 3). Light beam incident normally on the face A B is totally reflected to reach the face B C if (A)  sin θ > 8 / 9 (B) 2 / 3 < sin θ < 8 / 9 (C)  sin θ ≤ 2 / 3 (D)  cos θ ≥ 8 / 9

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/44585cd50574cd14ec8bf06e0caba6e5-.png" /> By applying Snell's law on face AC sin θ ≥ (8/9).

Q. A glass prism of refractive index $1.5$ is immersed in water $(μ = 4/3)$ . Light beam incident normally on the face $A B$ is totally reflected to reach the face $BC$ if

$sin θ > 8/9$

$2/3 < sin θ < 8/9$

$sin θ \leq 2/3$

$cos θ \geq 8/9$

By applying Snell's law on face $A C$
$sin θ \geq \frac{8}{9}$ .

Q. A glass prism of refractive index 1.5 is immersed in water (μ=4/3). Light beam incident normally on the face AB is totally reflected to reach the face BC if

sinθ>8/9

2/3<sinθ<8/9

sinθ≤2/3

cosθ≥8/9