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


Options
A.sin θ > 8/9
B.2/3 < sin θ > 8/9
C.sin θ > 2/3
D.none of these
Solution

Let θc be the critical angle at face BC, then
sin θc =

Angle of incidence at athe face BC is i = θ
Total internal reflection (TIR) will take place on this surface if
i > θc
or θ > θc
or sin θ > sin θ
or sin θ >

∴ Correct option is (a).
Create a free account to view solution
View Solution FreeMore Geometrical Optics Questions
The cross-section of a prism is shown in the figure. One of its refracting surfaces AC is given by y = x2. A ray of ligh...The unit of luminous efficiency of an electric bulb is:...Which of the following quantities related to a lens does not depend on the wavelength of the incident light ?...If √ î denotes a unit vector along incident light ray, a unit vector along refracted ray into a medium of ref...A prism of angle $75^{\circ}$ and refractive index $\sqrt{3}$ is coated with thin film of refractive index 1.5 only at t...