Question

A light ray is incident normally on the face AB of a right-angled prism ABC (μ= 1.50) as shown in figure (18 E9). What is the largest angle ϕ for which the light ray is totally reflected at the surface AC ?

Answer 1

Given :

(μ= 1.50

let θc be the critical angle for glass

sin θc/ sin 90= 1/x

sinθc= 1/1.5=2/3

θc= sin⁻¹[2/3]

For total internal reflection 90° -Ф>θc

θ<90°=θc

θ<cos⁻¹(2/3)

so largest angle for which light is totally reflected at the surface is cos⁻¹(2/3)

Answer 2

$\huge\mathfrak{\pink{Your\:Answer}}$
$<b>$____________________________________
GIVEN => (u = 1.50 .____________________________________
let 0c be the critical Angele for glass.

sin ~0~c/sin 90 =1/x.

sin ~0~c = 1/1.5=> 2/3.

0c= sin ^-1™[2/3]

FOR TOTAL INTERNAL REFLECTION 90°..
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FINAL ANSWER =-™[2/3]