Q.

Unpolarised light is incident on the boundary between two dielectric media, whose dielectric constants are 2.8 (medium-1) and 6.8 (medium-2), respectively. To satisfy the condition, so that the reflected and refracted rays are perpendicular to each other, the angle of incidence should be tan-1(1+10θ)12; the value of θ is ______. (Given for dielectric media, μr=1)                           [2023]
 


Ans.

(7)

μ1=2.8×1=2.8

μ2=6.8×1=6.8

μ1sini=μ2cosi

tani=μ2μ1=6.82.8

tan-1i=(2.8+42.8)1/2

i=tan-1(1+107)1/2

θ=7